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