diff --git a/docs/index.rst b/docs/index.rst
index 1b9b6fe..f89daba 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -20,7 +20,7 @@ Installation
 
 .. md-tab-set::
 
-   .. md-tab-item:: Pip + PyPI (recommented)
+   .. md-tab-item:: Pip + PyPI (recommended)
 
       .. code-block:: console
 
diff --git a/openapi_schema_validator/_keywords.py b/openapi_schema_validator/_keywords.py
index 6692580..a5de04e 100644
--- a/openapi_schema_validator/_keywords.py
+++ b/openapi_schema_validator/_keywords.py
@@ -1,8 +1,5 @@
-from copy import deepcopy
 from typing import Any
-from typing import Dict
 from typing import Hashable
-from typing import ItemsView
 from typing import Iterator
 from typing import List
 from typing import Mapping
@@ -112,7 +109,7 @@ def type(
         # * nullable: true is only meaningful in combination with a type
         #   assertion specified in the same Schema Object.
         # * nullable: true operates within a single Schema Object
-        if "nullable" in schema and schema["nullable"] == True:
+        if "nullable" in schema and schema["nullable"] is True:
             return
         yield ValidationError("None for not nullable")
 
diff --git a/openapi_schema_validator/shortcuts.py b/openapi_schema_validator/shortcuts.py
index d922bb8..fee0196 100644
--- a/openapi_schema_validator/shortcuts.py
+++ b/openapi_schema_validator/shortcuts.py
@@ -16,6 +16,19 @@ def validate(
     *args: Any,
     **kwargs: Any
 ) -> None:
+    """
+    Validate an instance against a given schema using the specified validator class
+
+    Args:
+        instance: The instance to validate.
+        schema: The schema to validate against
+        cls: The validator class to use (defaults to OAS31Validator)
+        *args: Additional positional arguments to pass to the validator
+        **kwargs: Additional keyword arguments to pass to the validator
+
+    Raises:
+        jsonschema.exceptions.ValidationError: If the instance is invalid according to the schema
+    """
     cls.check_schema(schema)
     validator = cls(schema, *args, **kwargs)
     error = best_match(validator.evolve(schema=schema).iter_errors(instance))
diff --git a/openapi_schema_validator/validators.py b/openapi_schema_validator/validators.py
index 44b5a42..8c5195e 100644
--- a/openapi_schema_validator/validators.py
+++ b/openapi_schema_validator/validators.py
@@ -1,7 +1,3 @@
-import warnings
-from typing import Any
-from typing import Type
-
 from jsonschema import _keywords
 from jsonschema import _legacy_keywords
 from jsonschema.validators import Draft202012Validator
diff --git a/tests/unit/test_shortcut.py b/tests/unit/test_shortcut.py
index 0ec80c7..0ceaa3e 100644
--- a/tests/unit/test_shortcut.py
+++ b/tests/unit/test_shortcut.py
@@ -1,21 +1,33 @@
-from unittest import TestCase
-
+import pytest
 from openapi_schema_validator import validate
 
 
-class ValidateTest(TestCase):
-    def test_validate_does_not_mutate_schema_adding_nullable_key(self):
-        schema = {
-            "type": "object",
-            "properties": {
-                "email": {"type": "string"},
-                "enabled": {
-                    "type": "boolean",
-                },
+@pytest.fixture(scope="function")
+def schema():
+    return {
+        "type": "object",
+        "properties": {
+            "email": {"type": "string"},
+            "enabled": {
+                "type": "boolean",
             },
-            "example": {"enabled": False, "email": "foo@bar.com"},
-        }
+        },
+        "example": {"enabled": False, "email": "foo@bar.com"},
+    }
+
+
+def test_validate_does_not_add_nullable_to_schema(schema):
+    """
+    Verify that calling validate does not add the 'nullable' key to the schema
+    """
+    validate({"email": "foo@bar.com"}, schema)
+    assert "nullable" not in schema["properties"]["email"].keys()
 
-        validate({"email": "foo@bar.com"}, schema)
 
-        self.assertTrue("nullable" not in schema["properties"]["email"].keys())
+def test_validate_does_not_mutate_schema(schema):
+    """
+    Verify that calling validate does not mutate the schema
+    """
+    original_schema = schema.copy()
+    validate({"email": "foo@bar.com"}, schema)
+    assert schema == original_schema