public function scopeGetUserChats($query, $userId) {
        /* this is the old code where i do not need is_blocked flag
            return $query->where('user_one_id', $userId)
                    ->orWhere('user_two_id', $userId);
        */
    //this is my new query
        $a = $query->where('user_one_id', $userId)
            ->orWhere('user_two_id', $userId)
            ->join('users_blocks', function($q) {
                $q->on(app('db')->raw('(users_blocks.user_id = chats.user_one_id and users_blocks.blocked_user_id =  chats.user_two_id) or (users_blocks.user_id = chats.user_two_id  and users_blocks.blocked_user_id = chats.user_one_id)'),            app('db')->raw(''), app('db')->raw(''));
                    })
            ->select('chats.id as chat_id', 'users_blocks.id as users_b_id', 'users_blocks.user_id', 'users_blocks.blocked_user_id', app('db')->raw('(CASE WHEN users_blocks.id IS NOT null then 1 else 0) as is_blocked'));
        //dd($a->toSql());
                    return $a;

    }