code: def get_class(mcs):
          
          if mcs._generated_class is None:
              mcs._generated_class = type(
                  mcs._cls_name,
                  tuple(mcs._base_classes),
                  {'_generated': True})
          return mcs._generated_class
docs: Generates new class to gether logic of all available extensions
              ::
  
                  mc = ExtensibleType._("MyClass")
                  @six.add_metaclass(mc)
                  class MyClassBase(object):
                      pass
  
                  # get class with all extensions enabled
                  MyClass = mc.get_class()