old_contents: from __future__ import absolute_import
  
  from ast import *
  
  from .version_info import PY2
  
  if PY2:
      Try = TryExcept
  else:
      TryFinally = ()
  
new_contents: from __future__ import absolute_import
  
  from ast import *
  
  from .version_info import PY2
  
  if PY2:
      Try = TryExcept
  
      def argument_names(node):
          return [isinstance(arg, Name) and arg.id or None for arg in node.args.args]
  
      def kw_only_argument_names(node):
          return []
  
      def kw_only_default_count(node):
          return 0
  else:
      TryFinally = ()
  
      def argument_names(node):
          return [arg.arg for arg in node.args.args]
  
      def kw_only_argument_names(self):
          return [arg.arg for arg in node.args.kwonlyargs]
  
      def kw_only_default_count(self):
          return sum(1 for n in node.args.kw_defaults if n is not None)
  
subject: Add aditional ast cross python version compatibility support