code: def testNestedTypes(self):
      self.assertEquals(
          set(unittest_pb2.TestAllTypes.DESCRIPTOR.nested_types),
          set(
              [
                  unittest_pb2.TestAllTypes.NestedMessage.DESCRIPTOR,
                  unittest_pb2.TestAllTypes.OptionalGroup.DESCRIPTOR,
                  unittest_pb2.TestAllTypes.RepeatedGroup.DESCRIPTOR,
              ]
          ),
      )
      self.assertEqual(
          unittest_pb2.TestEmptyMessage.DESCRIPTOR.nested_types, []
      )
      self.assertEqual(
          unittest_pb2.TestAllTypes.NestedMessage.DESCRIPTOR.nested_types,
          [],
      )
  
imports: import unittest
  from google.protobuf.internal import test_bad_identifiers_pb2
  from google.protobuf import unittest_custom_options_pb2
  from google.protobuf import unittest_import_pb2
  from google.protobuf import unittest_import_public_pb2
  from google.protobuf import unittest_mset_pb2
  from google.protobuf import unittest_pb2
  from google.protobuf import unittest_no_generic_services_pb2
  from google.protobuf import service
label_desc: Use image node_id 10 for calling the GeneratorTest obj's underlying member method code with example usage: obj.testNestedTypes() without return types