public function instantiateClasses()
    {
        $data = $this->getData();

        // Always load these
        if (isset($data['always']))
        {
            $this->instantiateGroup($data['always']);
        }

        // These only in admin
        if (is_admin() && isset($data['admin']))
        {
            $this->instantiateGroup($data['admin']);
        }

        // These only in frontend
        if ( !is_admin() && isset($data['frontend']))
        {
            $this->instantiateGroup($data['frontend']);
        }
    }