Used the IsSubclassOf method

instead of the IsAssignableFrom method.
Renamed the class

to BuildingSpecimenBuilderFactory.
Introduced the MockPostProcessor class

instead of MockedSpecimenBuilder and refactored some members of it.
Refactored the fuction

to check whether the Moq assembly exists.
Extracted the TypeExtensions class

from the MockExtensions class.
Added the explicit unit tests

to test to load the Moq assembly if the assembly is only needed.
Removed the unused using directive.
Refactored the test.
Removed the unused using directives.
Refactored to extract the FixtureFactory class.
Refactored the FixtureFactory class.
Extracted the LoadedAssemblies method.
Used the IsType method

instead of the DoesNotThrow method because Mock.Get can return NULL.
Refactored the LoadedAssemblies method.
Added the unit test

to test to load unique assemblies. As this test fails if run with other
tests, the test is skipped.
Installed the Moq package to AutoFixture.Contrib.
Deleted the AutoFixture.AutoMoq.Contrib.UnitTest

project.
Addressed adding the Moq reference directly.
Modified the test

because the two DynamicProxyGenAssembly2 assemblies are loaded
originally.
Removed the unnecessary CanEnableAutoMock

property.