ZoneUnaryCallback bindUnaryCallback(
dynamic f(arg),
{bool runGuarded: true}
)

Equivalent to:

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

Source

/**
 *  Equivalent to:
 *
 *      ZoneCallback registered = registerUnaryCallback(f);
 *      if (runGuarded) return (arg) => this.runUnaryGuarded(registered, arg);
 *      return (arg) => thin.runUnary(registered, arg);
 */
ZoneUnaryCallback bindUnaryCallback(f(arg), { bool runGuarded: true });