public function plugin_active( $plugin_file, $plugin_name ) {
		return $this->add_check(
			function() use ( $plugin_file ) {
				return in_array(
					$plugin_file,
					(array) get_option( 'active_plugins' ),
					true
				);
			},
			sprintf( '%s must be installed and active', $plugin_name )
		);
	}