const ZoneSpecification({HandleUncaughtErrorHandler handleUncaughtError(Zone self, ZoneDelegate parent, Zone zone, error, StackTrace stackTrace), RunHandler run(Zone self, ZoneDelegate parent, Zone zone, R f()), RunUnaryHandler runUnary(Zone self, ZoneDelegate parent, Zone zone, R f(T arg), T arg), RunBinaryHandler runBinary(Zone self, ZoneDelegate parent, Zone zone, R f(T1 arg1, T2 arg2), T1 arg1, T2 arg2), RegisterCallbackHandler registerCallback(Zone self, ZoneDelegate parent, Zone zone, R f()), RegisterUnaryCallbackHandler registerUnaryCallback(Zone self, ZoneDelegate parent, Zone zone, R f(T arg)), RegisterBinaryCallbackHandler registerBinaryCallback(Zone self, ZoneDelegate parent, Zone zone, R f(T1 arg1, T2 arg2)), ErrorCallbackHandler errorCallback(Zone self, ZoneDelegate parent, Zone zone, Object error, StackTrace stackTrace), ScheduleMicrotaskHandler scheduleMicrotask(Zone self, ZoneDelegate parent, Zone zone, void f()), CreateTimerHandler createTimer(Zone self, ZoneDelegate parent, Zone zone, Duration duration, void f()), CreatePeriodicTimerHandler createPeriodicTimer(Zone self, ZoneDelegate parent, Zone zone, Duration period, void f(Timer timer)), PrintHandler print(Zone self, ZoneDelegate parent, Zone zone, String line), ForkHandler fork(Zone self, ZoneDelegate parent, Zone zone, ZoneSpecification specification, Map zoneValues)})

Creates a specification with the provided handlers.

Source 

const factory ZoneSpecification({
    HandleUncaughtErrorHandler handleUncaughtError,
    RunHandler run,
    RunUnaryHandler runUnary,
    RunBinaryHandler runBinary,
    RegisterCallbackHandler registerCallback,
    RegisterUnaryCallbackHandler registerUnaryCallback,
    RegisterBinaryCallbackHandler registerBinaryCallback,
    ErrorCallbackHandler errorCallback,
    ScheduleMicrotaskHandler scheduleMicrotask,
    CreateTimerHandler createTimer,
    CreatePeriodicTimerHandler createPeriodicTimer,
    PrintHandler print,
    ForkHandler fork
}) = _ZoneSpecification;