@Test
    public void testGetCustomDefinition_withMappingReturningNull() {
        CustomDefinitionProviderV2 provider = Mockito.mock(CustomDefinitionProviderV2.class);
        Mockito.when(this.typesInGeneralConfigPart.getCustomDefinitionProviders()).thenReturn(Collections.singletonList(provider));
        ResolvedType javaType = Mockito.mock(ResolvedType.class);
        Assertions.assertNull(this.instance.getCustomDefinition(javaType, this.getContext(), null));

        // ensure that the provider has been called and the given java type and type variable context were forward accordingly
        Mockito.verify(provider).provideCustomSchemaDefinition(javaType, this.getContext());
    }
Test for the {@link SchemaGeneratorConfigImpl} class.
jsonschema-generator/src/test/java/com/github/victools/jsonschema/generator/impl/SchemaGeneratorConfigImplTest.java