code: def append_bump_sequence_op(self, bump_to, source=None):
          
          op = operation.BumpSequence(bump_to, source)
          return self.append_op(op)
docs: Append a :class:`BumpSequence <stellar_base.operation.BumpSequence>`
          operation to the list of operations.
  
          Only available in protocol version 10 and above
  
          :param int bump_to: Sequence number to bump to.
          :param str source: The source address that is running the inflation
              operation.
          :return: This builder instance.