Cannot parse a spec where the component schema name is the string "null"

[spacether]

master branch v2.1.1 cannot parse the below spec:
Can the project be updated so it can parse specs where the property names are the string null? That string is a valid name.
This worked in older versions of swagger-parser.

openapi: 3.0.1
info:
  title: Test for Kotlin reserved words
  version: 1.0.0
paths: {}
components:
  schemas:
    null:
      title: Testing reserved word 'null'
      type: object
      properties:
        id:
          type: integer
          format: int64
    Good:
      description: OK, Good
      type: object
      properties:
        null:
          type: string

And throws the error:

[main] WARN io.swagger.v3.parser.util.DeserializationUtils - Error snake-parsing yaml content
java.lang.IllegalArgumentException: Null key for a Map not allowed in JSON (use a converting NullKeySerializer?) (through reference chain: java.util.LinkedHashMap["components"]->java.util.LinkedHashMap["schemas"]->java.util.LinkedHashMap["Good"]->java.util.LinkedHashMap["properties"]->java.util.LinkedHashMap["null"])
	at com.fasterxml.jackson.databind.ObjectMapper._convert(ObjectMapper.java:4393)
	at com.fasterxml.jackson.databind.ObjectMapper.convertValue(ObjectMapper.java:4324)
	at io.swagger.v3.parser.util.DeserializationUtils.readYamlTree(DeserializationUtils.java:208)
	at io.swagger.v3.parser.util.DeserializationUtils.deserializeIntoTree(DeserializationUtils.java:140)
	at io.swagger.v3.parser.OpenAPIV3Parser.readContents(OpenAPIV3Parser.java:162)
	at io.swagger.v3.parser.OpenAPIV3Parser.readLocation(OpenAPIV3Parser.java:91)
	at io.swagger.parser.OpenAPIParser.readLocation(OpenAPIParser.java:16)
	at org.openapitools.codegen.TestUtils.parseSpec(TestUtils.java:71)
	at org.openapitools.codegen.TestUtils.parseFlattenSpec(TestUtils.java:54)
	at org.openapitools.codegen.kotlin.KotlinReservedWordsTest.<init>(KotlinReservedWordsTest.java:24)
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490)
	at org.testng.internal.objects.InstanceCreator.newInstance(InstanceCreator.java:38)
	at org.testng.ITestObjectFactory.newInstance(ITestObjectFactory.java:18)
	at org.testng.internal.objects.SimpleObjectDispenser.instantiateUsingDefaultConstructor(SimpleObjectDispenser.java:178)
	at org.testng.internal.objects.SimpleObjectDispenser.createInstance(SimpleObjectDispenser.java:87)
	at org.testng.internal.objects.SimpleObjectDispenser.dispense(SimpleObjectDispenser.java:40)
	at org.testng.internal.objects.GuiceBasedObjectDispenser.dispense(GuiceBasedObjectDispenser.java:28)
	at org.testng.internal.ClassImpl.getDefaultInstance(ClassImpl.java:106)
	at org.testng.internal.ClassImpl.getInstances(ClassImpl.java:136)
	at org.testng.TestClass.getInstances(TestClass.java:129)
	at org.testng.TestClass.initTestClassesAndInstances(TestClass.java:109)
	at org.testng.TestClass.init(TestClass.java:101)
	at org.testng.TestClass.<init>(TestClass.java:66)
	at org.testng.TestRunner.initMethods(TestRunner.java:465)
	at org.testng.TestRunner.init(TestRunner.java:333)
	at org.testng.TestRunner.init(TestRunner.java:286)
	at org.testng.TestRunner.<init>(TestRunner.java:176)
	at org.testng.SuiteRunner$DefaultTestRunnerFactory.newTestRunner(SuiteRunner.java:635)
	at org.testng.SuiteRunner.init(SuiteRunner.java:221)
	at org.testng.SuiteRunner.<init>(SuiteRunner.java:114)
	at org.testng.TestNG.createSuiteRunner(TestNG.java:1342)
	at org.testng.TestNG.createSuiteRunners(TestNG.java:1318)
	at org.testng.TestNG.runSuitesLocally(TestNG.java:1160)
	at org.testng.TestNG.runSuites(TestNG.java:1092)
	at org.testng.TestNG.run(TestNG.java:1060)
	at com.intellij.rt.testng.IDEARemoteTestNG.run(IDEARemoteTestNG.java:66)
	at com.intellij.rt.testng.RemoteTestNGStarter.main(RemoteTestNGStarter.java:109)
Caused by: com.fasterxml.jackson.databind.JsonMappingException: Null key for a Map not allowed in JSON (use a converting NullKeySerializer?) (through reference chain: java.util.LinkedHashMap["components"]->java.util.LinkedHashMap["schemas"]->java.util.LinkedHashMap["Good"]->java.util.LinkedHashMap["properties"]->java.util.LinkedHashMap["null"])
	at com.fasterxml.jackson.databind.JsonMappingException.from(JsonMappingException.java:283)

[spacether]

Sorry for filing this.
It was my mistake. This is not a real bug. It went away when I used the required version of swagger-core.