class_docstr: Tests assertProtoEqual().
code: def testMsgPassdown(self):
      self.assertRaisesRegex(
          AssertionError,
          "test message passed down",
          self.assertProtoEqual,
          "medium: {}",
          'medium: { smalls: { strings: "x" } }',
          msg="test message passed down",
      )
  
imports: import copy
  import re
  import sys
  import textwrap
  from google.protobuf import text_format
  from tensorflow.python.platform import googletest
  from tensorflow.python.util.protobuf import compare
  from tensorflow.python.util.protobuf import compare_test_pb2
label_desc: Use image node_id 13 for calling the AssertTest obj's underlying member method code with example usage: obj.testMsgPassdown() without return types