public static function create( $slug, $filename = '' ) {
		// Use the calling file as the main plugin file.
		if ( empty( $filename ) ) {
			$backtrace = debug_backtrace( DEBUG_BACKTRACE_PROVIDE_OBJECT, 1 );
			$filename = $backtrace[0]['file'];
		}

		return ( new Plugin() )
			->set_basename( plugin_basename( $filename ) )
			->set_directory( plugin_dir_path( $filename ) )
			->set_file( $filename )
			->set_slug( $slug )
			->set_url( plugin_dir_url( $filename ) );
	}