<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def copy(self):
 """ Copy the grammar. """

        new = self.__class__()
        for dict_attr in ("symbol2number", "number2symbol", "dfas", "keywords",
                          "tokens", "symbol2label"):
            setattr(new, dict_attr, getattr(self, dict_attr).copy())
        new.labels = self.labels[:]
        new.states = self.states[:]
        new.start = self.start
        return new