def prepare(self, left_tree, right_tree):
        """prepare() is run on the trees before diffing

        This is so the formatter can apply magic before diffing."""
        # We don't want to diff comments:
        self._remove_comments(left_tree)
        self._remove_comments(right_tree)

        self.placeholderer.do_tree(left_tree)
        self.placeholderer.do_tree(right_tree)
def prepare ( self , left_tree , right_tree ) : self . _remove_comments ( left_tree ) self . _remove_comments ( right_tree ) self . placeholderer . do_tree ( left_tree ) self . placeholderer . do_tree ( right_tree )
prepare() is run on the trees before diffing

        This is so the formatter can apply magic before diffing.