code: def set_source_ref(self, value):
          
          if value is None or not isinstance(value, str):
              raise TypeError("SourceRef is required and must be set to a String")
          else:
              self.__source_ref = value
docs: Setter for 'source_ref' field.
          :param value - a new value of 'source_ref' field. Required field. Must be a String type.