public function compoundInsert(array $quill)
    {
        if (count($quill['attributes']) > 0) {
            if (is_array($quill['insert']) === false) {
                $delta = new Compound($quill['insert']);

                foreach ($quill['attributes'] as $attribute => $value) {
                    $delta->setAttribute($attribute, $value);
                }

                $this->deltas[] = $delta;
            }
        }
    }