Adds one or more flags to the query.

        For example:
            current-patch-set -> --current-patch-set

def add_flags(self, *flags):
        """Adds one or more flags to the query.

        For example:
            current-patch-set -> --current-patch-set
        """
        if not isinstance(flags, (list, tuple)):
            flags = [str(flags)]

        self.extend(["--%s" % f for f in flags])
        return self