voku / Arrayy

     * @return static

     *                <p>(Immutable)</p>

     */

    public function moveElementToFirstPlace($key): self

    {

        $array = $this->getArray();

        if ($this->offsetExists($key)) {

            $tmpValue = $this->get($key);

            unset($array[$key]);

            $array = [$key => $tmpValue] + $array;

        }

        return static::create(

            $array,

            $this->iteratorClass,

            false

        );

    }

    /**

     * Move an array element to the last place.

     * @return static

     *                <p>(Immutable)</p>

     */

    public function moveElementToLastPlace($key): self

    {

        $array = $this->getArray();

        if ($this->offsetExists($key)) {

            $tmpValue = $this->get($key);

            unset($array[$key]);

            $array += [$key => $tmpValue];

        }

        return static::create(

            $array,

            $this->iteratorClass,

            false

        );

    }

    /**

     * Get the first key from the current array.