return emptySet();
  }

  protected Collection<Method> suppressForConcurrentSkipListSetWithComparator() {
    return emptySet();
  }

  public Test testsForCheckedNavigableSet() {
    return SortedSetTestSuiteBuilder.using(
            new TestStringSortedSetGenerator() {
              @Override
              public NavigableSet<String> create(String[] elements) {
                NavigableSet<String> innerSet = new TreeSet<>();

            CollectionSize.ANY)
        .suppressing(suppressForCheckedSet())
        .createTestSuite();
  }

  public Test testsForCheckedSortedSet() {
    return SortedSetTestSuiteBuilder.using(
            new TestStringSortedSetGenerator() {
              @Override
              public SortedSet<String> create(String[] elements) {
                SortedSet<String> innerSet = new TreeSet<>();

import com.google.common.collect.testing.MapInterfaceTest;
import com.google.common.collect.testing.SampleElements;
import com.google.common.collect.testing.SetTestSuiteBuilder;
import com.google.common.collect.testing.SortedSetTestSuiteBuilder;
import com.google.common.collect.testing.TestSetGenerator;
import com.google.common.collect.testing.TestStringCollectionGenerator;
import com.google.common.collect.testing.TestStringSetGenerator;