crash in _completePendingNativeResultIfNeeded

Unhandled Exception: type 'Null' is not a subtype of type 'Object'
#0 _AsyncCompleter.complete (dart:async/future_impl.dart:46:41)
#1 FlutterBoostAppState._completePendingNativeResultIfNeeded. (package:flutter_boost/flutter_boost_app.dart:521:28)
#2 List.forEach (dart:core-patch/growable_array.dart:403:8)
#3 FlutterBoostAppState._completePendingNativeResultIfNeeded (package:flutter_boost/flutter_boost_app.dart:520:10)
#4 FlutterBoostAppState.onContainerShow. (package:flutter_boost/flutter_boost_app.dart:545:13)
#5 new Future.delayed. (dart:async/future.dart:315:39)
#6 _rootRun (dart:async/zone.dart:1346:47)
#7 _CustomZone.run (dart:async/zone.dart:1258:19)
#8 _CustomZone.runGuarded (dart:async/zone.dart:1162:7)
#9 _CustomZone.bindCallbackGuarded. (dart:async/zone.dart:1202:23)


-----------------------------------
简单的示例
Completer myCompleter;
myCompleter = Completer();
debugPrint("do do do ");
myCompleter.complete();

必crash

Reproduce the reported Completer example, then inspect flutter_boost_app.dart around lines 520-521 in _completePendingNativeResultIfNeeded. Verify how the pending native result is completed when no value is supplied; done means the reported Null/Object crash no longer occurs.

Written by the indexing model from the issue text.