src/vs/base/parts/ipc/electron-main/ipcMain.ts/ValidatedIpcMain/once
class ValidatedIpcMain:	once(channel: string, listener: ipcMainListener): this {
		unsafeIpcMain.once(channel, (event: IpcMainEvent, ...args: any[]) => {
			if (this.validateEvent(channel, event)) {
				listener(event, ...args);
			}
		});

		return this;
	}