code: public static ImmutableSet<CopyOption> getCopyOptions(CopyOption... options) {
      ImmutableSet<CopyOption> result = ImmutableSet.copyOf(options);
      if (result.contains(ATOMIC_MOVE)) {
        throw new UnsupportedOperationException("'ATOMIC_MOVE' not allowed");
      }
      return result;
    }
docs: Returns an immutable set of the given options for a copy.