new_contents: #!/usr/bin/env python
  # -*- encoding: utf-8 -*-
  #
  # Copyright (c) 2016 ASMlover. All rights reserved.
  #
  # Redistribution and use in source and binary forms, with or without
  # modification, are permitted provided that the following conditions
  # are met:
  #
  #  * Redistributions of source code must retain the above copyright
  #    notice, this list ofconditions and the following disclaimer.
  #
  #  * Redistributions in binary form must reproduce the above copyright
  #    notice, this list of conditions and the following disclaimer in
  #    the documentation and/or other materialsprovided with the
  #    distribution.
  #
  # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  # FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  # BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  # POSSIBILITY OF SUCH DAMAGE.
  
  from collections import namedtuple
  
  Number = namedtuple('Number', ['value'])
  String = namedtuple('String', ['value'])
  Identifier = namedtuple('Identifier', ['value'])
  Assignment = namedtuple('Assignment', ['left', 'right'])
  BinaryOperator = namedtuple('BinaryOperator', ['operator', 'left', 'right'])
  UnaryOperator = namedtuple('UnaryOperator', ['operator', 'right'])
  Call = namedtuple('Call', ['left', 'arguments'])
  Function = namedtuple('Function', ['name', 'params', 'body'])
  Condition = namedtuple('Condition', ['cond', 'if_body', 'elifs', 'else_body'])
  Match = namedtuple('Match', ['cond', 'patterns', 'else_body'])
  WhileLoop = namedtuple('WhileLoop', ['cond', 'body'])
  ForLoop = namedtuple('ForLoop', ['var_name', 'collection', 'body'])
  Break = namedtuple('Break', [])
  Continue = namedtuple('Continue', [])
  Return = namedtuple('Return', ['value'])
  Array = namedtuple('Array', ['items'])
  Dictionary = namedtuple('Dictionary', ['items'])
  SubscriptOperator = namedtuple('SubscriptOperator', ['left', 'key'])
  Program = namedtuple('Program', ['body'])
  
subject: add AST for pylike