Returns a string representing the command you have to type to
        obtain the same packet

def command(self):
        """
        Returns a string representing the command you have to type to
        obtain the same packet
        """
        f = []
        for fn, fv in six.iteritems(self.fields):
            fld = self.get_field(fn)
            if isinstance(fv, (list, dict, set)) and len(fv) == 0:
                continue
            if isinstance(fv, Packet):
                fv = fv.command()
            elif fld.islist and fld.holds_packets and isinstance(fv, list):
                fv = "[%s]" % ",".join(map(Packet.command, fv))
            elif isinstance(fld, FlagsField):
                fv = int(fv)
            else:
                fv = repr(fv)
            f.append("%s=%s" % (fn, fv))
        c = "%s(%s)" % (self.__class__.__name__, ", ".join(f))
        pc = self.payload.command()
        if pc:
            c += "/" + pc
        return c