New inspection: Unnecessarily strong cast

InspectionGadgets notified me about the line

telling me that "Declaration of ArrayList should probably
be weakened to List".

I modified the line as suggested into this:

Strangely enough, after this change I get no inspection
telling me that the cast could be weakened.

Is this available already somewhere? If not, I think it's
a reasonable addition to make.

/Mikael