async def add_group_member(group_id: str, user_id: str) -> bool:
    """Adds a single user to a group."""
    try:
        if not user_id:
            return False
        
        request_body = ReferenceCreate(odata_id = f'https://graph.microsoft.com/v1.0/directoryObjects/{user_id}')
        await GRAPH_CLIENT.groups.by_group_id(group_id).members.ref.post(request_body)

        return True
    except Exception as e:
        raise e

async def add_group_members(group_id: str, user_ids: List[str]) -> bool:
    """Adds users to a group."""
    try:
        if not user_ids:
            return False
        elif len(user_ids) > 20:
            raise Exception("You can only add 20 users at a time.")
        elif len(user_ids) == 1:
            return await self.add_group_member(group_id, user_ids[0])

        request_body = Group(
            additional_data = {
                "members@odata_bind" : [f'https://graph.microsoft.com/v1.0/directoryObjects/{user_id}' for user_id in user_ids]
            }
        )
        await GRAPH_CLIENT.groups.by_group_id(group_id).patch(request_body)

        return True
    except Exception as e:
        raise e