code: static ClassInfoList getAllInterfacesOrAnnotationClasses(final Collection<ClassInfo> classes,
              final ScanSpec scanSpec) {
          return new ClassInfoList(ClassInfo.filterClassInfo(classes, scanSpec, /* strictWhitelist = */ true,
                  ClassType.INTERFACE_OR_ANNOTATION), /* sortByName = */ true);
      }
docs: Get all interface or annotation classes found during the scan. (Annotations are technically interfaces, and
  they can be implemented.)
  
  @param classes
  the classes
  @param scanSpec
  the scan spec
  @return A list of all whitelisted interfaces found during the scan, or the empty list if none.