code: def assertEqual(cls, first, second, msg=None):
          
          asserter = None
          if type(first) is type(second):
              asserter = cls.equality_type_funcs.get(type(first))
  
              try:              basestring = basestring # Python 2
              except NameError: basestring = str        # Python 3
  
              if asserter is not None:
                  if isinstance(asserter, basestring):
                      asserter = getattr(cls, asserter)
  
          if asserter is None:
              asserter = cls.simple_equality
  
          if msg is None:
              asserter(first, second)
          else:
              asserter(first, second, msg=msg)
docs: Classmethod equivalent to unittest.TestCase method