diff --git a/src/Elastic.Clients.Elasticsearch.Shared/Core/Extensions/Extensions.cs b/src/Elastic.Clients.Elasticsearch.Shared/Core/Extensions/Extensions.cs
index 52e3a14c5d1..81210225106 100644
--- a/src/Elastic.Clients.Elasticsearch.Shared/Core/Extensions/Extensions.cs
+++ b/src/Elastic.Clients.Elasticsearch.Shared/Core/Extensions/Extensions.cs
@@ -5,6 +5,7 @@
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Reflection;
 using System.Runtime.ExceptionServices;
@@ -172,13 +173,14 @@ internal static bool HasAny<T>(this IEnumerable<T> list, Func<T, bool> predicate
 
 	internal static bool HasAny<T>(this IEnumerable<T> list) => list != null && list.Any();
 
-	internal static bool IsEmpty<T>(this IEnumerable<T> list)
+	internal static bool IsNullOrEmpty<T>(this IEnumerable<T>? list)
 	{
-		if (list == null)
+		if (list is null)
 			return true;
 
 		var enumerable = list as T[] ?? list.ToArray();
-		return !enumerable.Any() || enumerable.All(t => t == null);
+
+		return (enumerable.Length == 0) || enumerable.All(x => x is null);
 	}
 
 	internal static void ThrowIfNull<T>(this T value, string name, string message = null)
@@ -189,9 +191,9 @@ internal static void ThrowIfNull<T>(this T value, string name, string message =
 			throw new ArgumentNullException(name, "Argument can not be null when " + message);
 	}
 
-	internal static bool IsNullOrEmpty(this string value) => string.IsNullOrWhiteSpace(value);
+	internal static bool IsNullOrEmpty(this string? value) => string.IsNullOrWhiteSpace(value);
 
-	internal static bool IsNullOrEmptyCommaSeparatedList(this string value, out string[] split)
+	internal static bool IsNullOrEmptyCommaSeparatedList(this string? value, [NotNullWhen(false)] out string[]? split)
 	{
 		split = null;
 		if (string.IsNullOrWhiteSpace(value))
diff --git a/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/Field/Field.cs b/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/Field/Field.cs
index 3075cbc7219..6ecff34ef00 100644
--- a/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/Field/Field.cs
+++ b/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/Field/Field.cs
@@ -4,24 +4,29 @@
 
 using System;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Text.Json.Serialization;
+
 using Elastic.Transport;
 
 #if ELASTICSEARCH_SERVERLESS
 namespace Elastic.Clients.Elasticsearch.Serverless;
 #else
+
 namespace Elastic.Clients.Elasticsearch;
 #endif
 
 [JsonConverter(typeof(FieldConverter))]
-[DebuggerDisplay("{" + nameof(DebugDisplay) + ",nq}")]
-public sealed class Field : IEquatable<Field>, IUrlParameter
+[DebuggerDisplay($"{nameof(DebuggerDisplay)},nq")]
+public sealed class Field :
+	IEquatable<Field>,
+	IUrlParameter
 {
 	private readonly object _comparisonValue;
-	private readonly Type _type;
+	private readonly Type? _type;
 
 	// Pseudo and metadata fields
 
@@ -30,143 +35,173 @@ public sealed class Field : IEquatable<Field>, IUrlParameter
 	public static Field KeyField = new("_key");
 	public static Field CountField = new("_count");
 
-	public Field(string name) : this(name, null, null) { }
+	/// <summary>
+	///     The name of the field
+	/// </summary>
+	public string? Name { get; }
+
+	/// <summary>
+	///     An expression from which the name of the field can be inferred
+	/// </summary>
+	public Expression? Expression { get; }
+
+	/// <summary>
+	///     A property from which the name of the field can be inferred
+	/// </summary>
+	public PropertyInfo? Property { get; }
+
+	/// <summary>
+	///     A boost to apply to the field
+	/// </summary>
+	public double? Boost { get; set; }
+
+	/// <summary>
+	///     A format to apply to the field.
+	/// </summary>
+	/// <remarks>
+	///     Can be used only for Doc Value Fields Elasticsearch 6.4.0+
+	/// </remarks>
+	public string? Format { get; set; }
+
+	internal bool CachableExpression { get; }
+
+	#region Constructors
+
+	public Field(string name) : this(name, null, null)
+	{
+	}
 
-	public Field(string name, double boost) : this(name, boost, null) { }
+	public Field(string name, double boost) : this(name, boost, null)
+	{
+	}
 
-	public Field(string name, string format) : this(name, null, format) { }
+	public Field(string name, string format) : this(name, null, format)
+	{
+	}
 
 	public Field(string name, double? boost, string? format)
 	{
-		name.ThrowIfNullOrEmpty(nameof(name));
+		if (string.IsNullOrEmpty(name))
+			throw new ArgumentException($"{name} can not be null or empty.", nameof(name));
+
 		Name = ParseFieldName(name, out var b);
 		Boost = b ?? boost;
 		Format = format;
+
 		_comparisonValue = Name;
 	}
 
-	public Field(Expression expression, double? boost = null, string format = null)
+	public Field(Expression expression, double? boost = null, string? format = null)
 	{
 		Expression = expression ?? throw new ArgumentNullException(nameof(expression));
 		Boost = boost;
 		Format = format;
+
 		_comparisonValue = expression.ComparisonValueFromExpression(out var type, out var cachable);
 		_type = type;
+
 		CachableExpression = cachable;
 	}
 
-	public Field(PropertyInfo property, double? boost = null, string format = null)
+	public Field(PropertyInfo property, double? boost = null, string? format = null)
 	{
 		Property = property ?? throw new ArgumentNullException(nameof(property));
 		Boost = boost;
 		Format = format;
+
 		_comparisonValue = property;
 		_type = property.DeclaringType;
 	}
 
-	/// <summary>
-	///     A boost to apply to the field
-	/// </summary>
-	public double? Boost { get; set; }
+	#endregion Constructors
 
-	/// <summary>
-	///     A format to apply to the field.
-	/// </summary>
-	/// <remarks>
-	///     Can be used only for Doc Value Fields Elasticsearch 6.4.0+
-	/// </remarks>
-	public string? Format { get; set; }
+	#region Factory Methods
 
-	internal bool CachableExpression { get; }
+	public static Field? FromString(string? name) => string.IsNullOrEmpty(name) ? null : new Field(name);
 
-	/// <summary>
-	///     An expression from which the name of the field can be inferred
-	/// </summary>
-	public Expression Expression { get; }
+	public static Field? FromExpression(Expression? expression) => expression is null ? null : new Field(expression);
 
-	/// <summary>
-	///     The name of the field
-	/// </summary>
-	public string Name { get; }
+	public static Field? FromProperty(PropertyInfo? property) => property is null ? null : new Field(property);
 
-	/// <summary>
-	///     A property from which the name of the field can be inferred
-	/// </summary>
-	public PropertyInfo Property { get; }
+	#endregion Factory Methods
 
-	internal string DebugDisplay =>
-		$"{Expression?.ToString() ?? PropertyDebug ?? Name}{(Boost.HasValue ? "^" + Boost.Value : string.Empty)}"
-		+ $"{(!string.IsNullOrEmpty(Format) ? " format: " + Format : string.Empty)}"
-		+ $"{(_type == null ? string.Empty : " typeof: " + _type.Name)}";
+	#region Conversion Operators
 
-	private string PropertyDebug => Property == null ? null : $"PropertyInfo: {Property.Name}";
+	public static implicit operator Field?(string? name) => FromString(name);
 
-	public bool Equals(Field other) => _type != null
-		? other != null && _type == other._type && _comparisonValue.Equals(other._comparisonValue)
-		: other != null && _comparisonValue.Equals(other._comparisonValue);
+	public static implicit operator Field?(Expression? expression) => FromExpression(expression);
 
-	string IUrlParameter.GetString(ITransportConfiguration settings)
+	public static implicit operator Field?(PropertyInfo? property) => FromProperty(property);
+
+	#endregion Conversion Operators
+
+	#region Combinator Methods
+
+	public Fields And(Field field)
 	{
-		if (settings is not IElasticsearchClientSettings elasticsearchSettings)
-		{
-			throw new ArgumentNullException(nameof(settings),
-				$"Can not resolve {nameof(Field)} if no {nameof(IElasticsearchClientSettings)} is provided");
-		}
+		if (field is null)
+			throw new ArgumentNullException(nameof(field));
 
-		return GetStringCore(elasticsearchSettings);
+		return new([this, field]);
 	}
 
-	private string GetStringCore(IElasticsearchClientSettings settings)
+	public Fields And<T, TValue>(Expression<Func<T, TValue>> expression, double? boost = null, string? format = null)
 	{
-		if (settings is null)
-		{
-			throw new ArgumentNullException(nameof(settings),
-				$"Can not resolve {nameof(Field)} if no {nameof(IElasticsearchClientSettings)} is provided");
-		}
+		if (expression is null)
+			throw new ArgumentNullException(nameof(expression));
 
-		return settings.Inferrer.Field(this);
+		return new([this, new Field(expression, boost, format)]);
 	}
 
-	public override string ToString() => DebugDisplay;
+	public Fields And<T>(Expression<Func<T, object>> expression, double? boost = null, string? format = null)
+	{
+		if (expression is null)
+			throw new ArgumentNullException(nameof(expression));
 
-	public Fields And(Field field) => new(new[] { this, field });
+		return new([this, new Field(expression, boost, format)]);
+	}
 
-	public Fields And<T, TValue>(Expression<Func<T, TValue>> field, double? boost = null, string format = null)
-		where T : class =>
-		new(new[] { this, new Field(field, boost, format) });
+	public Fields And(string field, double? boost = null, string? format = null)
+	{
+		if (field is null)
+			throw new ArgumentNullException(nameof(field));
 
-	public Fields And<T>(Expression<Func<T, object>> field, double? boost = null, string format = null)
-		where T : class =>
-		new(new[] { this, new Field(field, boost, format) });
+		return new([this, new Field(field, boost, format)]);
+	}
 
-	public Fields And(string field, double? boost = null, string format = null) =>
-		new(new[] { this, new Field(field, boost, format) });
+	public Fields And(PropertyInfo property, double? boost = null, string? format = null)
+	{
+		if (property is null)
+			throw new ArgumentNullException(nameof(property));
 
-	public Fields And(PropertyInfo property, double? boost = null, string format = null) =>
-		new(new[] { this, new Field(property, boost, format) });
+		return new([this, new Field(property, boost, format)]);
+	}
 
-	private static string ParseFieldName(string name, out double? boost)
-	{
-		boost = null;
-		if (name == null)
-			return null;
+	#endregion Combinator Methods
 
-		var caretIndex = name.IndexOf('^');
-		if (caretIndex == -1)
-			return name;
+	#region Equality
 
-		var parts = name.Split(new[] { '^' }, 2, StringSplitOptions.RemoveEmptyEntries);
-		name = parts[0];
-		boost = double.Parse(parts[1], CultureInfo.InvariantCulture);
-		return name;
-	}
+	public static bool operator ==(Field? a, Field? b) => Equals(a, b);
 
-	public static implicit operator Field(string name) => name.IsNullOrEmpty() ? null : new Field(name);
+	public static bool operator !=(Field? a, Field? b) => !Equals(a, b);
 
-	public static implicit operator Field(Expression expression) =>
-		expression == null ? null : new Field(expression);
+	public bool Equals(Field? other) =>
+		other switch
+		{
+			not null when _type is not null => (_type == other._type) && _comparisonValue.Equals(other._comparisonValue),
+			not null when _type is null => _comparisonValue.Equals(other._comparisonValue),
+			_ => false
+		};
 
-	public static implicit operator Field(PropertyInfo property) => property == null ? null : new Field(property);
+	public override bool Equals(object? obj) =>
+		obj switch
+		{
+			Field f => Equals(f),
+			string s => Equals(s),
+			Expression e => Equals(e),
+			PropertyInfo p => Equals(p),
+			_ => false
+		};
 
 	public override int GetHashCode()
 	{
@@ -178,22 +213,50 @@ public override int GetHashCode()
 		}
 	}
 
-	public override bool Equals(object obj)
+	#endregion Equality
+
+	#region IUrlParameter
+
+	string IUrlParameter.GetString(ITransportConfiguration settings)
 	{
-		switch (obj)
+		if (settings is not IElasticsearchClientSettings elasticsearchSettings)
 		{
-			case string s:
-				return Equals(s);
-			case PropertyInfo p:
-				return Equals(p);
-			case Field f:
-				return Equals(f);
-			default:
-				return false;
+			throw new ArgumentNullException(nameof(settings),
+				$"Can not resolve {nameof(Field)} if no {nameof(IElasticsearchClientSettings)} is provided");
 		}
+
+		return elasticsearchSettings.Inferrer.Field(this);
 	}
 
-	public static bool operator ==(Field x, Field y) => Equals(x, y);
+	#endregion IUrlParameter
+
+	#region Debugging
+
+	public override string ToString() =>
+		$"{Expression?.ToString() ?? PropertyDebug ?? Name}{(Boost.HasValue ? "^" + Boost.Value : string.Empty)}" +
+		$"{(!string.IsNullOrEmpty(Format) ? " format: " + Format : string.Empty)}" +
+		$"{(_type == null ? string.Empty : " typeof: " + _type.Name)}";
+
+	internal string DebuggerDisplay => ToString();
+
+	private string? PropertyDebug => Property is null ? null : $"PropertyInfo: {Property.Name}";
 
-	public static bool operator !=(Field x, Field y) => !Equals(x, y);
+	#endregion Debugging
+
+	[return: NotNullIfNotNull(nameof(name))]
+	private static string? ParseFieldName(string? name, out double? boost)
+	{
+		boost = null;
+		if (name is null)
+			return null;
+
+		var caretIndex = name.IndexOf('^');
+		if (caretIndex == -1)
+			return name;
+
+		var parts = name.Split(new[] { '^' }, 2, StringSplitOptions.RemoveEmptyEntries);
+		name = parts[0];
+		boost = double.Parse(parts[1], CultureInfo.InvariantCulture);
+		return name;
+	}
 }
diff --git a/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/Fields/Fields.cs b/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/Fields/Fields.cs
index dec3a645ad7..0112a9e2f2b 100644
--- a/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/Fields/Fields.cs
+++ b/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/Fields/Fields.cs
@@ -9,7 +9,7 @@
 using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
-using System.Text.Json;
+
 using Elastic.Transport;
 
 #if ELASTICSEARCH_SERVERLESS
@@ -18,141 +18,209 @@ namespace Elastic.Clients.Elasticsearch.Serverless;
 namespace Elastic.Clients.Elasticsearch;
 #endif
 
-[DebuggerDisplay("{DebugDisplay,nq}")]
-public sealed class Fields : IUrlParameter, IEnumerable<Field>, IEquatable<Fields>
+[DebuggerDisplay($"{nameof(DebuggerDisplay)},nq")]
+public sealed class Fields :
+	IEquatable<Fields>,
+	IEnumerable<Field>,
+	IUrlParameter
 {
 	internal readonly List<Field> ListOfFields;
 
-	internal Fields() => ListOfFields = new List<Field>();
+	#region Constructors
 
-	internal Fields(IEnumerable<Field> fieldNames) => ListOfFields = new List<Field>(fieldNames);
+	internal Fields() => ListOfFields = [];
 
-	private string DebugDisplay =>
-		$"Count: {ListOfFields.Count} [" +
-		string.Join(",", ListOfFields.Select((t, i) => $"({i + 1}: {t?.DebugDisplay ?? "NULL"})")) + "]";
+	internal Fields(IEnumerable<Field?> fields)
+	{
+		if (fields is null)
+			throw new ArgumentNullException(nameof(fields));
 
-	IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+		ListOfFields = [.. fields.Where(f => f is not null)];
+	}
 
-	public IEnumerator<Field> GetEnumerator() => ListOfFields.GetEnumerator();
+	#endregion Constructors
 
-	public bool Equals(Fields other) => EqualsAllFields(ListOfFields, other?.ListOfFields);
+	#region Factory Methods
 
-	string IUrlParameter.GetString(ITransportConfiguration? settings)
-	{
-		if (settings is not IElasticsearchClientSettings elasticsearchClientSettings)
-		{
-			throw new ArgumentNullException(nameof(settings),
-				$"Can not resolve {nameof(Fields)} if no {nameof(IElasticsearchClientSettings)} is provided");
-		}
+	public static Fields? FromField(Field? field) => field is null
+		? null
+		: new Fields([field]);
 
-		return string.Join(",",
-			ListOfFields.Where(f => f != null).Select(f => ((IUrlParameter)f).GetString(elasticsearchClientSettings)));
-	}
+	public static Fields? FromFields(Field[]? fields) => fields.IsNullOrEmpty()
+		? null
+		: new Fields(fields!);
 
-	public override string ToString() => DebugDisplay;
+	public static Fields? FromString(string? name) => name.IsNullOrEmptyCommaSeparatedList(out var split)
+		? null
+		: new Fields(split.Select(f => new Field(f)));
 
-	public static implicit operator Fields(string[] fields) =>
-		fields.IsEmpty() ? null : new Fields(fields.Select(f => new Field(f)));
+	public static Fields? FromStrings(string[]? names) => names.IsNullOrEmpty()
+		? null
+		: new Fields(names!.Select(f => new Field(f)));
 
-	public static implicit operator Fields(string field) => field.IsNullOrEmptyCommaSeparatedList(out var split)
+	public static Fields? FromExpression(Expression? expression) => expression is null
 		? null
-		: new Fields(split.Select(f => new Field(f)));
+		: new Fields([new Field(expression)]);
 
-	public static implicit operator Fields(Expression[] fields) =>
-		fields.IsEmpty() ? null : new Fields(fields.Select(f => new Field(f)));
+	public static Fields? FromExpressions(Expression[]? expressions) => expressions.IsNullOrEmpty()
+		? null
+		: new Fields(expressions!.Select(f => new Field(f)));
 
-	public static implicit operator Fields(Expression field) =>
-		field == null ? null : new Fields(new[] { new Field(field) });
+	public static Fields? FromExpression<T, TValue>(Expression<Func<T, TValue>>? expression) => expression is null
+		? null
+		: new Fields([new Field(expression)]);
 
-	public static implicit operator Fields(Field field) => field == null ? null : new Fields(new[] { field });
+	public static Fields? FromExpressions<T>(Expression<Func<T, object?>>[]? expressions) => expressions.IsNullOrEmpty()
+		? null
+		: new Fields(expressions!.Select(f => new Field(f)));
+
+	public static Fields? FromProperty(PropertyInfo? property) => property is null
+		? null
+		: new Fields([property]);
 
-	public static implicit operator Fields(PropertyInfo field) =>
-		field == null ? null : new Fields(new Field[] { field });
+	public static Fields? FromProperties(PropertyInfo[]? properties) => properties.IsNullOrEmpty()
+		? null
+		: new Fields(properties!.Select(f => new Field(f)));
 
-	public static implicit operator Fields(PropertyInfo[] fields) =>
-		fields.IsEmpty() ? null : new Fields(fields.Select(f => new Field(f)));
+	#endregion Factory Methods
 
-	public static implicit operator Fields(Field[] fields) => fields.IsEmpty() ? null : new Fields(fields);
+	#region Conversion Operators
 
-	public Fields And<T, TValue>(Expression<Func<T, TValue>> field, double? boost = null, string format = null)
-		where T : class
-	{
-		ListOfFields.Add(new Field(field, boost, format));
-		return this;
-	}
+	public static implicit operator Fields?(Field? field) => FromField(field);
+
+	public static implicit operator Fields?(Field[]? fields) => FromFields(fields);
+
+	public static implicit operator Fields?(string? name) => FromString(name);
+
+	public static implicit operator Fields?(string[]? names) => FromStrings(names);
+
+	public static implicit operator Fields?(Expression? expression) => FromExpression(expression);
+
+	public static implicit operator Fields?(Expression[]? expressions) => FromExpressions(expressions);
+
+	public static implicit operator Fields?(PropertyInfo? property) => FromProperty(property);
+
+	public static implicit operator Fields?(PropertyInfo[]? properties) => FromProperties(properties);
+
+	#endregion Conversion Operators
+
+	#region Combinator Methods
 
-	public Fields And(string field, double? boost = null, string format = null)
+	public Fields And(params Field?[] fields)
 	{
-		ListOfFields.Add(new Field(field, boost, format));
+		if (fields is null)
+			throw new ArgumentNullException(nameof(fields));
+
+		ListOfFields.AddRange(fields.Where(f => f is not null));
+
 		return this;
 	}
 
-	public Fields And(PropertyInfo property, double? boost = null)
+	public Fields And(params string?[] names)
 	{
-		ListOfFields.Add(new Field(property, boost));
+		if (names is null)
+			throw new ArgumentNullException(nameof(names));
+
+		ListOfFields.AddRange(names.Where(f => f is not null).Select(f => new Field(f)));
+
 		return this;
 	}
 
-	public Fields And<T>(params Expression<Func<T, object>>[] fields) where T : class
+	public Fields And<T>(params Expression<Func<T, object>>?[] expressions)
 	{
-		ListOfFields.AddRange(fields.Select(f => new Field(f)));
+		if (expressions is null)
+			throw new ArgumentNullException(nameof(expressions));
+
+		ListOfFields.AddRange(expressions.Where(f => f is not null).Select(f => new Field(f)));
+
 		return this;
 	}
 
-	public Fields And(params string[] fields)
+	public Fields And<T, TValue>(Expression<Func<T, TValue>> expression, double? boost = null, string? format = null)
+		where T : class
 	{
-		ListOfFields.AddRange(fields.Select(f => new Field(f)));
+		if (expression is null)
+			throw new ArgumentNullException(nameof(expression));
+
+		ListOfFields.Add(new Field(expression, boost, format));
+
 		return this;
 	}
 
-	public Fields And(params PropertyInfo[] properties)
+	public Fields And(params PropertyInfo?[] properties)
 	{
-		ListOfFields.AddRange(properties.Select(f => new Field(f)));
+		if (properties is null)
+			throw new ArgumentNullException(nameof(properties));
+
+		ListOfFields.AddRange(properties.Where(x => x is not null).Select(f => new Field(f)));
+
 		return this;
 	}
 
-	public Fields And(params Field[] fields)
+	#endregion Combinator Methods
+
+	#region Equality
+
+	public static bool operator ==(Fields? left, Fields? right) => Equals(left, right);
+
+	public static bool operator !=(Fields? left, Fields? right) => !Equals(left, right);
+
+	public override bool Equals(object? obj) =>
+		obj switch
+		{
+			Fields f => Equals(f),
+			Field[] f => Equals(f),
+			Field f => Equals(f),
+			string s => Equals(s),
+			string[] s => Equals(s),
+			Expression e => Equals(e),
+			Expression[] e => Equals(e),
+			PropertyInfo p => Equals(p),
+			PropertyInfo[] p => Equals(p),
+			_ => false
+		};
+
+	public override int GetHashCode() => ListOfFields.GetHashCode();
+
+	public bool Equals(Fields? other) => (ListOfFields, other?.ListOfFields) switch
 	{
-		ListOfFields.AddRange(fields);
-		return this;
-	}
+		(null, null) => true,
+		({ } a, { } b) => (a.Count == b.Count) && !a.Except(b).Any(),
+		_ => false
+	};
+
+	#endregion Equality
+
+	#region IEnumerable
+
+	IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
 
-	public static bool operator ==(Fields left, Fields right) => Equals(left, right);
+	public IEnumerator<Field> GetEnumerator() => ListOfFields.GetEnumerator();
+
+	#endregion IEnumerable
 
-	public static bool operator !=(Fields left, Fields right) => !Equals(left, right);
+	#region IUrlParameter
 
-	public override bool Equals(object obj)
+	string IUrlParameter.GetString(ITransportConfiguration? settings)
 	{
-		switch (obj)
+		if (settings is not IElasticsearchClientSettings elasticsearchClientSettings)
 		{
-			case Fields f:
-				return Equals(f);
-			case string s:
-				return Equals(s);
-			case Field fn:
-				return Equals(fn);
-			case Field[] fns:
-				return Equals(fns);
-			case Expression e:
-				return Equals(e);
-			case Expression[] es:
-				return Equals(es);
-			default:
-				return false;
+			throw new ArgumentNullException(nameof(settings),
+				$"Can not resolve {nameof(Fields)} if no {nameof(IElasticsearchClientSettings)} is provided");
 		}
-	}
 
-	private static bool EqualsAllFields(IReadOnlyList<Field> thisTypes, IReadOnlyList<Field> otherTypes)
-	{
-		if (thisTypes == null && otherTypes == null)
-			return true;
-		if (thisTypes == null || otherTypes == null)
-			return false;
-		if (thisTypes.Count != otherTypes.Count)
-			return false;
-
-		return thisTypes.Count == otherTypes.Count && !thisTypes.Except(otherTypes).Any();
+		return string.Join(",", ListOfFields.Select(f => ((IUrlParameter)f).GetString(elasticsearchClientSettings)));
 	}
 
-	public override int GetHashCode() => ListOfFields.GetHashCode();
+	#endregion IUrlParameter
+
+	#region Debugging
+
+	public override string ToString() =>
+		$"Count: {ListOfFields.Count} [" +
+		string.Join(",", ListOfFields.Select((t, i) => $"({i + 1}: {t?.DebuggerDisplay})")) + "]";
+
+	private string DebuggerDisplay => ToString();
+
+	#endregion Debugging
 }
diff --git a/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/Id/Ids.cs b/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/Id/Ids.cs
index 7e2fe48daf0..9385d4a80a7 100644
--- a/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/Id/Ids.cs
+++ b/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/Id/Ids.cs
@@ -66,7 +66,7 @@ public static implicit operator Ids(string value) =>
 		value.IsNullOrEmptyCommaSeparatedList(out var arr) ? null : new Ids(arr);
 
 	public static implicit operator Ids(string[] value) =>
-		value.IsEmpty() ? null : new Ids(value);
+		value.IsNullOrEmpty() ? null : new Ids(value);
 
 	public override bool Equals(object obj) => obj is Ids other && Equals(other);
 
diff --git a/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/Indices/Indices.cs b/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/Indices/Indices.cs
index 86a96c56df5..2a23cba5062 100644
--- a/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/Indices/Indices.cs
+++ b/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/Indices/Indices.cs
@@ -138,9 +138,9 @@ public static Indices Parse(string indicesString)
 
 	public static implicit operator Indices(string indicesString) => Parse(indicesString);
 
-	public static implicit operator Indices(string[] indices) => indices.IsEmpty() ? null : new Indices(indices);
+	public static implicit operator Indices(string[] indices) => indices.IsNullOrEmpty() ? null : new Indices(indices);
 
-	public static implicit operator Indices(IndexName[] indices) => indices.IsEmpty() ? null : new Indices(indices);
+	public static implicit operator Indices(IndexName[] indices) => indices.IsNullOrEmpty() ? null : new Indices(indices);
 
 	public static implicit operator Indices(IndexName index) => index == null ? null : new Indices(new[] { index });
 
diff --git a/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/JoinFieldRouting/Routing.cs b/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/JoinFieldRouting/Routing.cs
index 024545157a6..518c1420c64 100644
--- a/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/JoinFieldRouting/Routing.cs
+++ b/src/Elastic.Clients.Elasticsearch.Shared/Core/Infer/JoinFieldRouting/Routing.cs
@@ -94,7 +94,7 @@ public static implicit operator Routing(string routing) =>
 		routing.IsNullOrEmptyCommaSeparatedList(out _) ? null : new Routing(routing);
 
 	public static implicit operator Routing(string[] routing) =>
-		routing.IsEmpty() ? null : new Routing(string.Join(",", routing));
+		routing.IsNullOrEmpty() ? null : new Routing(string.Join(",", routing));
 
 	public static implicit operator Routing(long routing) => new(routing);
 
diff --git a/src/Elastic.Clients.Elasticsearch.Shared/Core/UrlParameters/DataStreamNames/DataStreamNames.cs b/src/Elastic.Clients.Elasticsearch.Shared/Core/UrlParameters/DataStreamNames/DataStreamNames.cs
index c7eb0bff77c..5c0bbfaf5b6 100644
--- a/src/Elastic.Clients.Elasticsearch.Shared/Core/UrlParameters/DataStreamNames/DataStreamNames.cs
+++ b/src/Elastic.Clients.Elasticsearch.Shared/Core/UrlParameters/DataStreamNames/DataStreamNames.cs
@@ -34,7 +34,7 @@ public sealed class DataStreamNames : IUrlParameter, IEnumerable<DataStreamName>
 
 	public override string ToString() => string.Join(",", Names.Where(f => f is not null).Select(f => f.Name));
 
-	public static implicit operator DataStreamNames(string[] dataStreamNames) => dataStreamNames.IsEmpty() ? null : new DataStreamNames(dataStreamNames.Select(f => new DataStreamName(f)));
+	public static implicit operator DataStreamNames(string[] dataStreamNames) => dataStreamNames.IsNullOrEmpty() ? null : new DataStreamNames(dataStreamNames.Select(f => new DataStreamName(f)));
 
 	public static implicit operator DataStreamNames(string dataStreamName) => dataStreamName.IsNullOrEmptyCommaSeparatedList(out var split)
 		? null
@@ -42,7 +42,7 @@ public static implicit operator DataStreamNames(string dataStreamName) => dataSt
 
 	public static implicit operator DataStreamNames(DataStreamName dataStreamName) => dataStreamName == null ? null : new DataStreamNames(new[] { dataStreamName });
 
-	public static implicit operator DataStreamNames(DataStreamName[] dataStreamNames) => dataStreamNames.IsEmpty() ? null : new DataStreamNames(dataStreamNames);
+	public static implicit operator DataStreamNames(DataStreamName[] dataStreamNames) => dataStreamNames.IsNullOrEmpty() ? null : new DataStreamNames(dataStreamNames);
 
 	IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
 
diff --git a/src/Elastic.Clients.Elasticsearch.Shared/Core/UrlParameters/Name/Names.cs b/src/Elastic.Clients.Elasticsearch.Shared/Core/UrlParameters/Name/Names.cs
index a66545cbf07..19f7e64c788 100644
--- a/src/Elastic.Clients.Elasticsearch.Shared/Core/UrlParameters/Name/Names.cs
+++ b/src/Elastic.Clients.Elasticsearch.Shared/Core/UrlParameters/Name/Names.cs
@@ -43,7 +43,7 @@ string IUrlParameter.GetString(ITransportConfiguration? settings) =>
 
 	public static implicit operator Names(string names) => Parse(names);
 
-	public static implicit operator Names(string[] names) => names.IsEmpty() ? null : new Names(names);
+	public static implicit operator Names(string[] names) => names.IsNullOrEmpty() ? null : new Names(names);
 
 	public static bool operator ==(Names left, Names right) => Equals(left, right);
 
diff --git a/src/Elastic.Clients.Elasticsearch.Shared/Core/UrlParameters/NodeIds/NodeIds.cs b/src/Elastic.Clients.Elasticsearch.Shared/Core/UrlParameters/NodeIds/NodeIds.cs
index 91095fd814e..38f045d330e 100644
--- a/src/Elastic.Clients.Elasticsearch.Shared/Core/UrlParameters/NodeIds/NodeIds.cs
+++ b/src/Elastic.Clients.Elasticsearch.Shared/Core/UrlParameters/NodeIds/NodeIds.cs
@@ -38,7 +38,7 @@ public NodeIds(IEnumerable<string> nodeIds)
 
 	public static implicit operator NodeIds(string nodes) => Parse(nodes);
 
-	public static implicit operator NodeIds(string[] nodes) => nodes.IsEmpty() ? null : new NodeIds(nodes);
+	public static implicit operator NodeIds(string[] nodes) => nodes.IsNullOrEmpty() ? null : new NodeIds(nodes);
 
 	public static bool operator ==(NodeIds left, NodeIds right) => Equals(left, right);
 
diff --git a/src/Elastic.Clients.Elasticsearch.Shared/Core/UrlParameters/ScrollIds/ScrollIds.cs b/src/Elastic.Clients.Elasticsearch.Shared/Core/UrlParameters/ScrollIds/ScrollIds.cs
index 2beb5475f10..d261b36c264 100644
--- a/src/Elastic.Clients.Elasticsearch.Shared/Core/UrlParameters/ScrollIds/ScrollIds.cs
+++ b/src/Elastic.Clients.Elasticsearch.Shared/Core/UrlParameters/ScrollIds/ScrollIds.cs
@@ -34,7 +34,7 @@ public sealed class ScrollIds : IUrlParameter, IEnumerable<ScrollId>, IEquatable
 
 	public override string ToString() => string.Join(",", Ids.Where(f => f is not null).Select(f => f.Id));
 
-	public static implicit operator ScrollIds(string[] scrollIds) => scrollIds.IsEmpty() ? null : new ScrollIds(scrollIds.Select(f => new ScrollId(f)));
+	public static implicit operator ScrollIds(string[] scrollIds) => scrollIds.IsNullOrEmpty() ? null : new ScrollIds(scrollIds.Select(f => new ScrollId(f)));
 
 	public static implicit operator ScrollIds(string scrollIds) => scrollIds.IsNullOrEmptyCommaSeparatedList(out var split)
 		? null
@@ -42,7 +42,7 @@ public static implicit operator ScrollIds(string scrollIds) => scrollIds.IsNullO
 
 	public static implicit operator ScrollIds(ScrollId scrollId) => scrollId == null ? null : new ScrollIds(new[] { scrollId });
 
-	public static implicit operator ScrollIds(ScrollId[] scrollIds) => scrollIds.IsEmpty() ? null : new ScrollIds(scrollIds);
+	public static implicit operator ScrollIds(ScrollId[] scrollIds) => scrollIds.IsNullOrEmpty() ? null : new ScrollIds(scrollIds);
 
 	IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();