code: def check_compiler_gcc4(cmd):
      """Return True if the C compiler is GCC 4.x."""
      cmd._check_compiler()
      body = """
  int
  main()
  {
  #if (! defined __GNUC__) || (__GNUC__ < 4)
  #error gcc >= 4 required
  #endif
      return 0;
  }
  """
      return cmd.try_compile(body, None, None)
  
imports: from __future__ import division, absolute_import, print_function
label_desc: Use image node_id 3 for calling a global function with example usage: check_compiler_gcc4(cmd) and returns: cmd