private function setMenuTitle( $menuTitle, $menuSlug = false )
    {
        $this->menuTitle   = $menuTitle;
        $this->menuSlug    = ( $menuSlug !== false ? sanitize_title($menuSlug) : sanitize_title($menuTitle) );
        $this->fieldPrefix = "__wex_{$this->menuSlug}_";
        $this->pageTitle   = $menuTitle;

        return $this;
    }