def register_macro(self, *macros):
        """ Registers macro classes passed a method arguments.
        """
        for m in macros:
            if inspect.isclass(m) and issubclass(m, macro_module.Macro):
                self.macros.append(m)
            else:
                raise TypeError("Coundn't register macro; a macro must inherit"
                                " from macro.Macro")
Registers macro classes passed a method arguments.