code: def _protobuf_value_to_string(value):
    
    value_in_json = json_format.MessageToJson(value)
    if value.HasField("string_value"):
      # Remove the quotations.
      return value_in_json[1:-1]
    return value_in_json
docs: Returns a string representation of given google.protobuf.Value message.
  
    Args:
      value: google.protobuf.Value message. Assumed to be of type 'number',
        'string' or 'bool'.