public function add_sub_page() {

		$this->screen_hook_suffix = add_submenu_page(
			$this->struct['args']['parent'],
			$this->struct['args']['page_title'],
			$this->struct['args']['menu_title'],
			$this->struct['args']['capability'],
			$this->slug,
			array( $this, 'create_page' )
		);

	}