old_contents: """ Introduce refactoring """
  
  import api
  
  
  class Refactoring(object):
      def __init__(self, changed_lines, renamed_files):
          self.changed_lines = changed_lines
          self.renamed_files = renamed_files
  
      def diff(self):
          return ''
  
  
  def refactor(operation, *args, **kwargs):
      """ The end of the params are the same as in:
      :param operation: The refactoring operation to execute.
      :type operation: str
      :return: list of changed lines/changed files
      """
      return globals()[operation](*args, **kwargs)
  
  def rename(new_name, *args, **kwargs):
      script = api.Script(*args, **kwargs)
      old_names = script.related_names()
  
      return []
  
new_contents: """ Introduce refactoring """
  
  import api
  
  
  class Refactoring(object):
      def __init__(self, changed_lines, renamed_files):
          self.changed_lines = changed_lines
          self.renamed_files = renamed_files
  
      def diff(self):
          return ''
  
  
  def rename(new_name, *args, **kwargs):
      """ The `args` / `kwargs` params are the same as in `api.Script`.
      :param operation: The refactoring operation to execute.
      :type operation: str
      :return: list of changed lines/changed files
      """
      script = api.Script(*args, **kwargs)
      old_names = script.related_names()
      return []
  
subject: remove generalized refactoring method for now