public void testSingletonMapFirst() {
    assertEquals(a.getKey(), navigableMap.firstKey());
  }

  @CollectionSize.Require(ONE)
  public void testSingletonMapLast() {
    assertEquals(a.getKey(), navigableMap.lastKey());
  }

  @CollectionSize.Require(SEVERAL)
  public void testFirst() {
    assertEquals(a.getKey(), navigableMap.firstKey());
  }

  @CollectionSize.Require(SEVERAL)
  public void testLast() {

  public void testSingletonMapFirst() {
    assertEquals(a.getKey(), navigableMap.firstKey());
  }

  @CollectionSize.Require(ONE)
  public void testSingletonMapLast() {
    assertEquals(a.getKey(), navigableMap.lastKey());
  }

  @CollectionSize.Require(SEVERAL)
  public void testFirst() {
    assertEquals(a.getKey(), navigableMap.firstKey());
  }

  @CollectionSize.Require(SEVERAL)
  public void testLast() {

    unfiltered.put("banana", 6);
    unfiltered.put("cat", 3);
    unfiltered.put("dog", 5);

    SortedMap<String, Integer> filtered = Maps.filterEntries(unfiltered, CORRECT_LENGTH);
    assertEquals("banana", filtered.firstKey());
    assertEquals("cat", filtered.lastKey());
  }

  public void testHeadSubTailMap_FilteredMap() {
    SortedMap<String, Integer> unfiltered = createUnfiltered();
    unfiltered.put("apple", 2);

      return new TreeRow(rowKey, fromKey, upperBound);
    }

    @Override
    public C firstKey() {
      updateBackingRowMapField();
      if (backingRowMap == null) {
        throw new NoSuchElementException();
      }
      return ((SortedMap<C, V>) backingRowMap).firstKey();
    }

    @Override
    public C lastKey() {
      updateBackingRowMapField();

        delegate().clear();
      }
    };
  }

  @Override
  public @Nullable Entry<K, V> firstEntry() {
    return delegate.firstEntry();
  }

  @Override
  public K firstKey() {
    return delegate.firstKey();
  }

  @Override
  public @Nullable Entry<K, V> floorEntry(K key) {
    return delegate.floorEntry(checkValid(key));
  }

  @Override
  public @Nullable K floorKey(K key) {

        delegate().clear();
      }
    };
  }

  @Override
  public @Nullable Entry<K, V> firstEntry() {
    return delegate.firstEntry();
  }

  @Override
  public K firstKey() {
    return delegate.firstKey();
  }

  @Override
  public @Nullable Entry<K, V> floorEntry(K key) {
    return delegate.floorEntry(checkValid(key));
  }

  @Override
  public @Nullable K floorKey(K key) {

    unfiltered.put("banana", 6);
    unfiltered.put("cat", 3);
    unfiltered.put("dog", 5);

    SortedMap<String, Integer> filtered = Maps.filterEntries(unfiltered, CORRECT_LENGTH);
    assertEquals("banana", filtered.firstKey());
    assertEquals("cat", filtered.lastKey());
  }

  public void testHeadSubTailMap_FilteredMap() {
    SortedMap<String, Integer> unfiltered = createUnfiltered();
    unfiltered.put("apple", 2);

			ext := tok.String()
			curArrangement, err := arch.ARM64RegisterArrangement(reg, name, ext)
			if err != nil {
				p.errorf(err.Error())
			}
			if firstReg == -1 {
				// only record the first register and arrangement
				firstReg = int(reg)
				nextReg = firstReg
				arrangement = curArrangement
			} else if curArrangement != arrangement {
				p.errorf("inconsistent arrangement in ARM64 register list")

    return ImmutableSortedSet.copyOf(comparator, sortedDelegate.keySet());
  }

  public Comparator<? super K> comparator() {
    return comparator;
  }

  @CheckForNull
  public K firstKey() {
    return sortedDelegate.firstKey();
  }

  @CheckForNull
  public K lastKey() {
    return sortedDelegate.lastKey();
  }

  @CheckForNull
  K higher(K k) {

    TreeMultimap<String, Integer> multimap = createPopulate();
    SortedMap<String, Collection<Integer>> asMap = multimap.asMap();
    assertEquals(Ordering.natural(), asMap.comparator());
    assertEquals("foo", asMap.firstKey());
    assertEquals("tree", asMap.lastKey());
    Set<Integer> fooValues = ImmutableSet.of(1, 3, 7);
    Set<Integer> googleValues = ImmutableSet.of(2, 6);
    Set<Integer> treeValues = ImmutableSet.of(4, 0);