code: def _ModifiedDecoder(wire_type, decode_value, modify_value):
    
  
    # 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)
docs: Like SimpleDecoder but additionally invokes modify_value on every value
    before storing it.  Usually modify_value is ZigZagDecode.