Method constructor

packages/firebase-auth/index.ios.ts:892–894

(app?: FirebaseApp)

export class Auth implements IAuth {
	_native: FIRAuth;
	constructor(app?: FirebaseApp) {
		this._app = app;
	}

	useEmulator(host: string, port: number) {
		this.native.useEmulatorWithHostPort(host, port);