public function key()
    {
        $element = $this->collection->current();
        
        if ($element !== false) {
            return $this->getKey($element);
        }
    }
public function key()
    {
        $element = $this->collection->current();
        
        if ($element !== false) {
            return $this->getKey($element);
        }
    }
{@inheritDoc}