@Override
    public List<String> order(List<String> insertionOrder) {
      sort(insertionOrder, Collections.reverseOrder());
      return insertionOrder;
    }
  }

  public static class ImmutableSortedSetUnhashableGenerator extends TestUnhashableSetGenerator {
    @Override
    public Set<UnhashableObject> create(UnhashableObject[] elements) {
      return ImmutableSortedSet.copyOf(elements);
    }
  }

    @Override
    public List<String> order(List<String> insertionOrder) {
      sort(insertionOrder, Collections.reverseOrder());
      return insertionOrder;
    }
  }

  public static class ImmutableSortedSetUnhashableGenerator extends TestUnhashableSetGenerator {
    @Override
    public Set<UnhashableObject> create(UnhashableObject[] elements) {
      return ImmutableSortedSet.copyOf(elements);
    }
  }

import com.google.common.collect.testing.google.SetGenerators.ImmutableSortedSetSubsetAsListGenerator;
import com.google.common.collect.testing.google.SetGenerators.ImmutableSortedSetUnhashableGenerator;
import com.google.common.collect.testing.testers.SetHashCodeTester;
import com.google.common.testing.CollectorTester;
import com.google.common.testing.NullPointerTester;