parameters: (self, old_path, new_path)
docstring: Rename a file or directory.
docstring_summary: Rename a file or directory.
docstring_tokens: Rename a file or directory .
function: def rename_file(self, old_path, new_path):
          """Rename a file or directory."""
          raise NotImplementedError('must be implemented in a subclass')
function_tokens: def rename_file ( self , old_path , new_path ) : raise NotImplementedError ( 'must be implemented in a subclass' )