async def add_recipients(self, *recipients):
        r"""|coro|

        Adds recipients to this group.

        A group can only have a maximum of 10 members.
        Attempting to add more ends up in an exception. To
        add a recipient to the group, you must have a relationship
        with the user of type :attr:`RelationshipType.friend`.

        Parameters
        -----------
        \*recipients: :class:`User`
            An argument list of users to add to this group.

        Raises
        -------
        HTTPException
            Adding a recipient to this group failed.
        """

        # TODO: wait for the corresponding WS event

        req = self._state.http.add_group_recipient
        for recipient in recipients:
            await req(self.id, recipient.id)