rex_string::buildAttributes PHP Method

    public static function buildAttributes(array $attributes)
    {
        $attr = '';
        foreach ($attributes as $key => $value) {
            if (is_int($key)) {
                $attr .= ' ' . $value;
            } else {
                if (is_array($value)) {
                    $value = implode(' ', $value);
                }
                $attr .= ' ' . $key . '="' . $value . '"';
            }
        }
        return $attr;
    }

    }
    $icon = '';
    if (isset($item['icon']) && $item['icon'] != '') {
        if (isset($item['itemAttr']['class'])) {
            if (is_array($item['itemAttr']['class'])) {
                $item['itemAttr']['class'] = array_merge($item['itemAttr']['class'], ['rex-has-icon']);
            } else {
                $item['itemAttr']['class'] = [$item['itemAttr']['class'], 'rex-has-icon'];
            }
        } else {
            $item['itemAttr']['class'] = ['rex-has-icon'];
        }
        $icon = '<i class="' . trim($item['icon']) . '"></i> ';
    }
    $itemAttr = isset($item['itemAttr']) ? rex_string::buildAttributes($item['itemAttr']) : '';
    $linkAttr = isset($item['linkAttr']) ? rex_string::buildAttributes($item['linkAttr']) : '';
    ?>

        <li<?php 
    echo $itemAttr;
    ?>
><a href="<?php 
    echo $item['href'];
    ?>
"<?php 
    echo $linkAttr;
    ?>
><?php 
    echo $icon . $item['title'];
    ?>
</a></li>