* <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingSortedMap} forward <i>indiscriminately</i> to
 * the methods of the delegate. For example, overriding {@link #put} alone <i>will not</i> change
 * the behavior of {@link #putAll}, which can lead to unexpected behavior. In this case, you should

 *
 * @author Louis Wasserman
 * @since 11.0
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class DoubleMath {
  /*
   * This method returns a value y such that rounding y DOWN (towards zero) gives the same result as
   * rounding x according to the specified mode.
   */
  @GwtIncompatible // #isMathematicalInteger, com.google.common.math.DoubleUtils

      @SuppressWarnings("unchecked") // safe since map is not writable
      ImmutableBiMap<K, V> bimap = (ImmutableBiMap<K, V>) map;
      // TODO(lowasser): if we need to make a copy of a BiMap because the
      // forward map is a view, don't make a copy of the non-view delegate map
      if (!bimap.isPartialView()) {
        return bimap;
      }
    }
    return copyOf(map.entrySet());
  }

  /**

   * of {@code iterator2}.
   *
   * <p>Note that this will modify the supplied iterators, since they will have been advanced some
   * number of elements forward.
   */
  public static boolean elementsEqual(Iterator<?> iterator1, Iterator<?> iterator2) {
    while (iterator1.hasNext()) {
      if (!iterator2.hasNext()) {
        return false;
      }

  private final transient ImmutableSortedMultiset<E> forward;

  DescendingImmutableSortedMultiset(ImmutableSortedMultiset<E> forward) {
    this.forward = forward;
  }

  @Override
  public int count(@CheckForNull Object element) {
    return forward.count(element);
  }

  @Override
  @CheckForNull
  public Entry<E> firstEntry() {
    return forward.lastEntry();
  }

  @Override
  @CheckForNull

  private final transient ImmutableSortedMultiset<E> forward;

  DescendingImmutableSortedMultiset(ImmutableSortedMultiset<E> forward) {
    this.forward = forward;
  }

  @Override
  public int count(@CheckForNull Object element) {
    return forward.count(element);
  }

  @Override
  @CheckForNull
  public Entry<E> firstEntry() {
    return forward.lastEntry();
  }

  @Override
  @CheckForNull

   * #iterator} to forward to this implementation.
   *
   * @since 7.0
   */
  protected Iterator<E> standardIterator() {
    return Multisets.iteratorImpl(this);
  }

  /**
   * A sensible, albeit inefficient, definition of {@link #size} in terms of {@link #entrySet}. If
   * you override {@link #entrySet}, you may wish to override {@link #size} to forward to this
   * implementation.
   *

   * this implementation.
   *
   * @since 7.0
   */
  protected Iterator<E> standardIterator() {
    return listIterator();
  }

  /**
   * A sensible default implementation of {@link #listIterator()}, in terms of {@link
   * #listIterator(int)}. If you override {@link #listIterator(int)}, you may wish to override
   * {@link #listIterator()} to forward to this implementation.
   *

 * the <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingSortedMultiset} forward
 * <b>indiscriminately</b> to the methods of the delegate. For example, overriding {@link
 * #add(Object, int)} alone <b>will not</b> change the behavior of {@link #add(Object)}, which can

  public void testFrom() {
    Function<String, Integer> forward =
        new Function<String, Integer>() {
          @Override
          public Integer apply(String input) {
            return Integer.parseInt(input);
          }
        };
    Function<Object, String> backward = toStringFunction();

    Converter<String, Number> converter = Converter.<String, Number>from(forward, backward);