public function main( $main_class = '' ) {
		if ( count( $containers = $this->containers() ) > 0 ) {
			echo '<main class="wplibs-box__container ' . esc_attr( $main_class ) . '">';
			$this->show_sections( $containers );
			echo '</main>';
		} else {
			$this->show_fields( $this->get_form()->all() );
		}
	}