Crash when call EasyHub.dismiss() immediately after EasyHub.showHub()

[623637646]

Demo code

EasyHub.showHub();
await EasyHub.dismiss();

Crash:

Exception has occurred.
NoSuchMethodError (NoSuchMethodError: The method 'pop' was called on null.
Receiver: null
Tried calling: pop(Closure: () => Null))

[623637646]

EasyHub.showHub();
await doSomethings();  // sometimes this call finishs in current run loop without "wait"
await EasyHub.dismiss();

The reason why I need to call EasyHub.dismiss() immediately after EasyHub.showHub() is that sometimes the doSomethings() return very fast in current run loop.