refactor: Resolving unchecked-cast warnings in ContractVerifier

[rishivijayv]

#4924

Not entirely sure if this is an acceptable fix because I don't feel too good about using SuppressWarnings here (and we generally seem to be against doing that as seen in #4925), but the unchecked cast issue here was caused by (Collection<CtElement>) attributeOfParent... and (Map<String, ?>) attributeOfParent.

I wasn't sure how to go about fixing these, since they weren't really related to returning this or super.clone() and a quick Google search wasn't helpful either (giving suggestions such as this)-- so I'm more than open to alternative ways of fixing this, if there are any!

Before

These 2 Warnings appeared when running mvn compile after a clean

...
[WARNING] .../ContractVerifier.java:[567,90] unchecked cast
  required: java.util.Collection<spoon.reflect.declaration.CtElement>
  found:    java.lang.Object
[WARNING] .../ContractVerifier.java:[572,83] unchecked cast
  required: java.util.Map<java.lang.String,?>
  found:    java.lang.Object
...

After

Those 2 warnings are gone! :)

@SirYwell would appreciate your thoughts on this, since I believe you've been involved with the effort in clearing out unchecked-cast warnings before 😅

[SirYwell]

I think both warnings can also be avoided by just using wildcard generics instead of concrete types. For the first one, == will still work, and for the second one, the type we operate on already is ?, just the String causes the warning - but we never need that at all.

[rishivijayv]

@SirYwell Ohh that's great! Updated the changes and the warnings are gone now even without SuppressWarning 😄

I'll have to look in to wildcard generics a little more as my knowledge of those is still a little flaky, but thanks for the tip! 🫡

[SirYwell]

Thanks, looks good.