/**
 *
 * Tell whether the platform is running on nirvana-js.
 *
 **/
export declare function isNirvana(): boolean;
/**
 *
 * Get the current browser window.
 *
 * @return A Electron's BrowserWindow object
 *
 **/
export declare function getCurrentWindow(): Electron.BrowserWindow | undefined;
/**
 *
 * Close the current browser process immediately.
 *
 * @param code: Exit code.
 *
 **/
export declare function exit(code?: number): void;
/**
 *
 * Captures a snapshot of the current window.
 *
 * @param fname: The location of captured PNG file.
 *
 **/
export declare function screenshot(fname: string): Promise<void>;