Collapse two collections to one in laravel

I need help with collapse my collections. Its my code

public function showFriends(){
            $request1 = DB::table('friends_users')
                ->join('users', 'users.id', '=', 'friends_users.user_id')
                ->where([['friend_id', '=',Auth::user()->id],['accepted', '=',true]])
                ->orWhere([['user_id','=',Auth::user()->id],['accepted','= ',true]])
                ->get();

                $request2 = DB::table('friends_users')
                ->join('users', 'users.id', '=', 'friends_users.friend_id')
                    ->where([['user_id','=',Auth::user()->id] , ['accepted','=',true]])
                    ->get();

                    $all = collect($request1,$request2)->collapse();
        return $all;

    }

Problem is in $all variable because it return empty collection. Thank you for help.

via kacper1230