Returns the right parameter set class.

def dispatch_hook(cls, _pkt=None, *args, **kargs):
        """
        Returns the right parameter set class.
        """

        cls = conf.raw_layer
        if _pkt is not None:
            ptype = orb(_pkt[0])
            return globals().get(_param_set_cls.get(ptype), conf.raw_layer)

        return cls