private static @NotNull SynchronizedBidiMultiMap<RefEntity, CommonProblemDescriptor> createBidiMap() {
    return new SynchronizedBidiMultiMap<>() {
      @Override
      protected @NotNull ArrayFactory<CommonProblemDescriptor> arrayFactory() {
        return CommonProblemDescriptor.ARRAY_FACTORY;
      }
    };
  }
private static @NotNull SynchronizedBidiMultiMap<RefEntity, CommonProblemDescriptor> createBidiMap()