def TryAppend(self, line, line_num):
      """Try appending a line.

      Args:
        line: The line to append.
        line_num: The number of the line.

      Returns:
        A tuple of (SUCCESS, CAN_ADD_MORE).  If SUCCESS if False, the line
        wasn't append.  If SUCCESS is True, then CAN_ADD_MORE is True/False to
        indicate if more lines can be added after this one.
      """
      assert False, "subclass should have overridden"
      return (False, False)
Try appending a line.

      Args:
        line: The line to append.
        line_num: The number of the line.

      Returns:
        A tuple of (SUCCESS, CAN_ADD_MORE).  If SUCCESS if False, the line
        wasn't append.  If SUCCESS is True, then CAN_ADD_MORE is True/False to
        indicate if more lines can be added after this one.
      
deps/protobuf/objectivec/DevTools/pddm.py