<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _ModifiedDecoder(wire_type, decode_value, modify_value):
 """Like SimpleDecoder but additionally invokes modify_value on every value before storing it. Usually modify_value is ZigZagDecode. """


  # Reusing _SimpleDecoder is slightly slower than copying a bunch of code, but
  # not enough to make a significant difference.

  def InnerDecode(buffer, pos):
    (result, new_pos) = decode_value(buffer, pos)
    return (modify_value(result), new_pos)
  return _SimpleDecoder(wire_type, InnerDecode)