code: def test_identity(self):
      assert_is(
          compose_types(C),
          C,
          msg="compose_types of a single class should be identity",
      )
  
imports: from zipline.testing.fixtures import ZiplineTestCase
  from zipline.testing.predicates import assert_equal, assert_is, assert_is_instance, assert_is_subclass, assert_true
  from zipline.utils.metautils import compose_types, with_metaclasses
label_desc: Use image node_id 1 for calling the ComposeTypesTestCase obj's underlying member method code with example usage: obj.test_identity() without return types