framework/data/BaseDataProvider.php
public function init()
    {
        parent::init();
        if ($this->id === null) {
            if (self::$counter > 0) {
                $this->id = 'dp-' . self::$counter;
            }
            self::$counter++;
        }
    }
public function init()
    {
        parent::init();
        if ($this->id === null) {
            if (self::$counter > 0) {
                $this->id = 'dp-' . self::$counter;
            }
            self::$counter++;
        }
    }
{@inheritdoc}