A little game with PHP MULTYARRAY

Css_helper.php

<?php
function enqueue_css()
{
    $default = $array = array(
        array(
            'name' => 'Bootstrap',
            'id' => 'bootstrap-css',
            'url' => 'https://stackpath.bootstrapcdn.com/bootstrap/5.0.0-alpha1/css/bootstrap.min.css',
            'version' => 5,
            'parent' => NULL,
            'position' => 0,
        ),
        array(
            'name' => 'Toolbar',
            'id' => 'toolbar-css',
            'url' => 'toolbar.css',
            'version' => 5,
            'parent' => NULL,
            'position' => 1,
        ),
        [
            'name' => 'Other Primary',
            'id' => 'other-css',
            'url' => 'other.css',
            'version' => 5,
            'parent' => NULL,
            'position' => 2,
        ],
        [
            'name' => 'Buttons',
            'id' => 'buttons',
            'url' => NULL,
            'version' => NULL,
            'parent' => 'bootstrap-css',
            'position' => 0,
        ],
        [
            'name' => 'Smile',
            'id' => 'smile',
            'url' => NULL,
            'version' => NULL,
            'parent' => 'other-css',
            'position' => 1,
        ]
    );


    echo "First, parents";


    print_r(sortCss($array, 'position', null, 'parent'));


    echo "<br/>--<br /><br />";
    echo "Second,childrens <br />";


    print_r(sortCss($array, 'position', 'parent', null));


    echo "<br />";
    echo "<br />";
    echo "<br />";
}


function sortCss($array, $value = null, $IncludeValue = null, $ExcludeValue = null)
{
    /*
     * check if is array
     */
    if (!is_array($array)) {
        return "Var send is not array";
    }
    /*
     * check if key really exist in array
     */
    if (!array_key_exists($value, $array[0])) {
        return "Var not exist!!";
    }
    /*
     * try to exclude from array
     */
    if ($ExcludeValue !== null && array_key_exists($ExcludeValue, $array[0])) {
        foreach ($array as $key => $value) {
            if ($value[$ExcludeValue] !== NULL || strlen($value[$ExcludeValue])>0) {
                unset($array[$key]);
            }
        }
    }
    /*
     * try to include in array JUST WHO have this value = $includeValue
     */
    if ($IncludeValue !== null && (array_key_exists($IncludeValue, $array[0]))) {
        foreach ($array as $key => $value) {
            if ($value[$IncludeValue] == NULL) {
                unset($array[$key]);
            }
        }
    }
    /*
     * finally, we try to sort
     */
    usort($array, function ($a, $b) {
        if ($a['position'] === $b['position']) {
            return 0;
        }
        return ($a['position'] < $b['position']) ? 1 : -1;
    });
    return $array;
}