public function exists(string $taskID, string $listID = ''): bool
    {
        $list = $this->getListData($listID);
        if (isset($list[$taskID])) {
            $app = App::get();
            return $app->data->exists($this->getTaskDataKey($taskID, $listID));
        }
        return false;
    }
public function exists(string $taskID, string $listID = ''): bool
    {
        $list = $this->getListData($listID);
        if (isset($list[$taskID])) {
            $app = App::get();
            return $app->data->exists($this->getTaskDataKey($taskID, $listID));
        }
        return false;
    }
public function exists ( string $ taskID , string $ listID = '' ) : bool { $ list = $ this -> getListData ( $ listID ) ; if ( isset ( $ list [ $ taskID ] ) ) { $ app = App :: get ( ) ; return $ app -> data -> exists ( $ this -> getTaskDataKey ( $ taskID , $ listID ) ) ; } return false ; }
Checks if a task exists.

@param string $taskID The ID of the task.
@param string $listID The ID of the tasks lists.
@return boolean
Checks if a task exists .