ZoneUnaryCallback bindUnaryCallback(dynamic action(argument), { bool runGuarded: true })

Equivalent to:

 ZoneCallback registered = this.registerUnaryCallback(action);
 if (runGuarded) return (arg) => this.runUnaryGuarded(registered, arg);
 return (arg) => thin.runUnary(registered, arg);

Source

ZoneUnaryCallback/*<R, T>*/ bindUnaryCallback/*<R, T>*/(
    /*=R*/ action(/*=T*/ argument), { bool runGuarded: true });