SDK: 2.12 version casting problem

[kenjishiromajp]

Hi guys I'm having this issue because of the new version.

══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
The following _CastError was thrown building
InnerDrawer-[LabeledGlobalKey<InnerDrawerState>#4b9dd](dirty, dependencies: [_InheritedTheme,
MediaQuery, _EffectiveTickerMode, _LocalizationsScope-[GlobalKey#f63de]], state:
InnerDrawerState#d2fd7(ticker inactive)):
type 'List<Widget?>' is not a subtype of type 'List<Widget>' in type cast

The problem is caused because of casting, it's a simple fix and it works... can you guys have a look?

[mixable]

I can confirm that the changes of this request solves the issue. I have the same CastError when using the latest version in combination with SDK 2.12.

[pythoneer]

Can i help to further push a merge and a release to this PR? The fix looks good to me and works for the cases i have tested and is equivalent to the one i made without noticing this one here thus having closed it in favor to this one being merged faster.

[deakjahn]

Another small nag... Publish it, please...

[mixable]

@Dn-a how can we support you to publish these changes?

[Allyanora]

Hi, when do you think this fix will this merged? I have two apps based on this package and cannot run it at all without this small fix.

Is there an issue why one of these pull request fixing this issue wasn't merged until now? If so, can you please tell us how can we help to fix this asap? Thank you.