@Override
  protected SortedMap<String, Integer> makeEmptyMap() {
    return new SimpleForwardingSortedMap<>(
        new TreeMap<String, Integer>(Ordering.<String>natural().nullsFirst()));
  }

  @Override
  protected SortedMap<String, Integer> makePopulatedMap() {
    final SortedMap<String, Integer> sortedMap = makeEmptyMap();
    sortedMap.put("one", 1);
    sortedMap.put("two", 2);
    sortedMap.put("three", 3);

    suite.addTest(
        SortedMapTestSuiteBuilder.using(
                new TestStringSortedMapGenerator() {
                  @Override
                  protected SortedMap<String, String> create(Entry<String, String>[] entries) {
                    SortedMap<String, String> map = new NonNavigableSortedMap();
                    putEntries(map, entries);
                    map.putAll(ENTRIES_TO_FILTER);

    SortedMap<Integer, Character> row = sortedTable.row("c");
    assertEquals(2, row.size());
    assertEquals(1, row.tailMap(15).size());
  }

  public void testSubRowClearAndPut() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    SortedMap<Integer, Character> row = (SortedMap<Integer, Character>) table.row("foo");
    SortedMap<Integer, Character> subRow = row.tailMap(2);

  @Override
  public SortedMap<K, V> subMap(@ParametricNullness K fromKey, @ParametricNullness K toKey) {
    return subMap(fromKey, true, toKey, false);
  }

  @Override
  public SortedMap<K, V> headMap(@ParametricNullness K toKey) {
    return headMap(toKey, false);
  }

  @Override
  public SortedMap<K, V> tailMap(@ParametricNullness K fromKey) {

        delegate.subMap(checkValid(fromKey), fromInclusive, checkValid(toKey), toInclusive));
  }

  @Override
  public SortedMap<K, V> subMap(K fromKey, K toKey) {
    return subMap(fromKey, true, toKey, false);
  }

  @Override
  public SortedMap<K, V> tailMap(K fromKey) {
    return tailMap(fromKey, true);
  }

  @Override
  public NavigableMap<K, V> tailMap(K fromKey, boolean inclusive) {

        delegate.subMap(checkValid(fromKey), fromInclusive, checkValid(toKey), toInclusive));
  }

  @Override
  public SortedMap<K, V> subMap(K fromKey, K toKey) {
    return subMap(fromKey, true, toKey, false);
  }

  @Override
  public SortedMap<K, V> tailMap(K fromKey) {
    return tailMap(fromKey, true);
  }

  @Override
  public NavigableMap<K, V> tailMap(K fromKey, boolean inclusive) {

import com.google.common.collect.testing.TestStringListGenerator;
import com.google.common.collect.testing.TestStringSortedMapGenerator;
import java.util.Arrays;
import java.util.List;
import java.util.Map.Entry;
import java.util.SortedMap;

/**
 * Generators of sorted maps and derived collections.
 *
 * @author Kevin Bourrillion
 * @author Jesse Wilson
 * @author Jared Levy
 * @author Hayward Chan
 * @author Chris Povirk

    assertTrue(multimap.asMap() instanceof SortedMap);
  }

  public void testTreeKeys_gwtCompatible() {
    ListMultimap<String, Integer> multimap =
        rawtypeToWildcard(MultimapBuilder.treeKeys()).arrayListValues().<String, Integer>build();
    assertTrue(multimap.keySet() instanceof SortedSet);
    assertTrue(multimap.asMap() instanceof SortedMap);
  }

import com.google.common.annotations.GwtCompatible;
import java.util.SortedMap;

@GwtCompatible
@ElementTypesAreNonnullByDefault
public class FilteredSortedMapTest extends AbstractFilteredMapTest {
  @Override
  SortedMap<String, Integer> createUnfiltered() {
    return Maps.newTreeMap();
  }

  public void testFirstAndLastKeyFilteredMap() {
    SortedMap<String, Integer> unfiltered = createUnfiltered();

      Map<? extends K, ? extends V> map, Comparator<? super K> comparator) {
    boolean sameComparator = false;
    if (map instanceof SortedMap) {
      SortedMap<?, ?> sortedMap = (SortedMap<?, ?>) map;
      Comparator<?> comparator2 = sortedMap.comparator();
      sameComparator =
          (comparator2 == null) ? comparator == NATURAL_ORDER : comparator.equals(comparator2);
    }