class_docstr: Checks that messages, enums and files are correctly registered.
code: def testGetSymbol(self):
      self.assertEqual(
          unittest_pb2.TestAllTypes,
          symbol_database.Default().GetSymbol(
              "protobuf_unittest.TestAllTypes"
          ),
      )
      self.assertEqual(
          unittest_pb2.TestAllTypes.NestedMessage,
          symbol_database.Default().GetSymbol(
              "protobuf_unittest.TestAllTypes.NestedMessage"
          ),
      )
      with self.assertRaises(KeyError):
          symbol_database.Default().GetSymbol(
              "protobuf_unittest.NestedMessage"
          )
      self.assertEqual(
          unittest_pb2.TestAllTypes.OptionalGroup,
          symbol_database.Default().GetSymbol(
              "protobuf_unittest.TestAllTypes.OptionalGroup"
          ),
      )
      self.assertEqual(
          unittest_pb2.TestAllTypes.RepeatedGroup,
          symbol_database.Default().GetSymbol(
              "protobuf_unittest.TestAllTypes.RepeatedGroup"
          ),
      )
  
imports: 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_mset_wire_format_pb2
  from google.protobuf import unittest_no_generic_services_pb2
  from google.protobuf import unittest_pb2
  from google.protobuf import service
  from google.protobuf import symbol_database
label_desc: Use image node_id 1 for calling the SymbolDatabaseRegistrationTest obj's underlying member method code with example usage: obj.testGetSymbol() without return types