1 - compiler.warn.incubating.modules: jdk.incubator.mvt
   2 - compiler.err.warnings.and.werror
   3 CheckNullCastable.java:10:54: compiler.warn.prob.found.req: (compiler.misc.inconvertible.types: compiler.misc.type.null, CheckNullCastable)
   4 CheckNullCastable.java:11:17: compiler.warn.incomparable.types: CheckNullCastable, compiler.misc.type.null
   5 CheckNullCastable.java:11:17: compiler.warn.value.does.not.support: !=
   6 CheckNullCastable.java:12:18: compiler.warn.incomparable.types: compiler.misc.type.null, CheckNullCastable
   7 CheckNullCastable.java:12:18: compiler.warn.value.does.not.support: !=
   8 1 error
   9 6 warnings