code: def test_gen123(self):
      @decorator
      def square(func, *args, **kw):
          for x in gen123():
              yield x * x
  
      new = square(gen123)
      self.assertTrue(inspect.isgeneratorfunction(new))
      self.assertEqual(list(new()), [1, 4, 9])
  
imports: from __future__ import absolute_import
  import sys
  import doctest
  import unittest
  import decimal
  import inspect
  import functools
  import collections
  from collections import defaultdict
  from decorator import dispatch_on, contextmanager, decorator
label_desc: Use image node_id 1 for calling the GeneratorCallerTestCase obj's underlying member method code with example usage: obj.test_gen123() without return types