public function splice($offset = 0, $length = 0, $replacement = null)
        {
            $array = $this->get();
            if (null !== $replacement) {
                array_splice($array, $offset, $length, $replacement);
            } else {
                array_splice($array, $offset, $length);
            }
            $this->update($array);
            return $this;
        }