Bad state: No element

[LGang]

线上出现几百个异常日志，本地测试无法复现。

872行代码片段截图

堆栈信息：
#0 ListMixin.reduce (dart:collection/list.dart:222)
#1 _CrossAxisChildrenData.insert (package:waterfall_flow/src/rendering/sliver_waterfall_flow.dart:872)
#2 RenderSliverWaterfallFlow.performLayout (package:waterfall_flow/src/rendering/sliver_waterfall_flow.dart:537)
#3 RenderObject.layout (package:flutter/src/rendering/object.dart:1915)
#4 RenderSliverEdgeInsetsPadding.performLayout (package:flutter/src/rendering/sliver_padding.dart:137)
#5 RenderSliverPadding.performLayout (package:flutter/src/rendering/sliver_padding.dart:371)
#6 RenderObject.layout (package:flutter/src/rendering/object.dart:1915)
#7 RenderViewportBase.layoutChildSequence (package:flutter/src/rendering/viewport.dart:510)
#8 RenderViewport._attemptLayout (package:flutter/src/rendering/viewport.dart:1580)
#9 RenderViewport.performLayout (package:flutter/src/rendering/viewport.dart:1489)
#10 RenderObject._layoutWithoutResize (package:flutter/src/rendering/object.dart:1757)
#11 PipelineOwner.flushLayout (package:flutter/src/rendering/object.dart:887)
#12 RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:504)
#13 WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:892)
#14 RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:370)
#15 SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1146)
#16 SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1083)
#17 SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:997)
#18 _rootRun (dart:async/zone.dart:1426)
#19 _CustomZone.run (dart:async/zone.dart:1328)
#20 _CustomZone.runGuarded (dart:async/zone.dart:1236)
#21 _invoke (dart:ui/hooks.dart:151)
#22 PlatformDispatcher._drawFrame (dart:ui/platform_dispatcher.dart:308)
#23 _drawFrame (dart:ui/hooks.dart:115)

[zmtzawqlp]

最好是有demo，不然我也很难去调试原因