slices() architecture should take a DescribedPredicate<JavaClass>

[xenoterracide]

I slice and layer to get module boundaries.

The pain I'm experiencing is that a slices() has matching(String) but for layers I can pass a DescribedPredicate this is resulting in code duplication, and exposing strings.

this is also related to #1534 in that I want to use some of the same predicates or sub predicates, as the layer predicates are often using and( and or( from what I would use for slices

slices().that(resideInAPackage("domain.aggregate.(*)"))

static class Domain {

   static DescribedPredicate<JavaClass> AGGREGATE = residesInAPackage("domain.aggregate.(*)")
   static DescribedPredicate<JavaClass> SERVICE = residesInAPackage("domain.service")

   static Layer layer() {
     return new Layer("Domain", or(AGGREGATE, SERVICE);
   }
}

slices()
   .that(Domain.AGGREGATE) // note: layer is a value object and thus any instance with the same 
value...
   .should()
   .notDependOnEachOther()