Insert an element before and after certain array key of an associative array

insert_element.php

<?php

    /**
     * Insert an element before certain array key of an associative array.
     * If no key is found,the element will be inserted at the end
     *
     * @since 1.0.0
     *
     * @param array $origin The original array where the element will be inserted
     * @param mixed $element The element to insert
     * @param string $key The key that will be searched to insert the element before.
     * @return array
     */
    private function insert_element_before($origin, $element, $key) {

        # Get key position
        $keys = array_keys( $origin );
        $index = array_search( $key, $keys, true );
        $pos = false === $index ? count( $origin ) : $index;

        return array_merge( array_slice( $origin, 0, $pos ), $element, array_slice( $origin, $pos ) );
    }

    /**
     * Insert an element after certain array key of an associative array.
     * If no key is found, the element will be inserted at the end
     *
     * @since 1.0.0
     *
     * @param array $origin The original array where the element will be inserted
     * @param mixed $element The element to insert
     * @param string $key The key that will be searched to insert the element before.
     * @return array
     */
    private function insert_element_after($origin, $element, $key) {

        # Get key position
        $keys = array_keys( $origin );
        $index = array_search( $key, $keys, true );
        $pos = false === $index ? count( $origin ) : $index + 1;

        return array_merge( array_slice( $origin, 0, $pos ), $element, array_slice( $origin, $pos ) );
    }