new_contents: #-----------------------------------------------------------------
  # pycparser: func_write.py
  #
  # Tiny example of rewriting a AST node
  #
  # Copyright (C) 2014, Akira Hayakawa
  # License: BSD
  #-----------------------------------------------------------------
  from __future__ import print_function
  import sys
  
  from pycparser import c_parser
  
  text = r"""
  void func(void)
  {
  	x = 1;
  }
  """
  
  parser = c_parser.CParser()
  ast = parser.parse(text)
  print("Before:")
  ast.show(offset=2)
  
  assign = ast.ext[0].body.block_items[0]
  assign.lvalue.name = "y"
  assign.rvalue.value = 2
  
  print("After:")
  ast.show(offset=2)
  
subject: add example of rewriting AST node