Method return values are allowed to be marked with @Valid in parallel methods, but the RI throws an exception.

Test: ValidMethodConstraintDeclarationTest.testReturnValueMarkedAsCascadedInParallelInterfaces()

No group conversion must be specified in this case, though. The RI does not throw an exception in this situation.

Tests:

• InvalidGroupDefinitionsTest.testGroupConversionGivenOnReturnValueInParallelInterfaces()
• InvalidGroupDefinitionsTest.testGroupConversionGivenOnReturnValueInSuperClassAndImplementedInterface()