* <p>If the mapped keys contain duplicates (according to {@link Object#equals(Object)}), the
   * values are merged using the specified merging function. If the merging function returns {@code
   * null}, then the collector removes the value that has been computed for the key thus far (though
   * future occurrences of the key would reinsert it).
   *
   * <p>Entries will appear in the encounter order of the first occurrence of the key.
   *

   */
  @SuppressWarnings({"AndroidJdkLibsChecker", "Java7ApiChecker"})
  @IgnoreJRERequirement // Users will use this only if they're already using streams.
  @Beta // TODO: b/288085449 - Remove.
  public static <T extends @Nullable Object, K extends Comparable<? super K>, V>
      Collector<T, ?, ImmutableRangeMap<K, V>> toImmutableRangeMap(
          Function<? super T, Range<K>> keyFunction,

   */
  @SuppressWarnings({"AndroidJdkLibsChecker", "Java7ApiChecker"})
  @IgnoreJRERequirement // Users will use this only if they're already using streams.
  @Beta // TODO: b/288085449 - Remove.
  public static <E extends Comparable<? super E>>
      Collector<Range<E>, ?, ImmutableRangeSet<E>> toImmutableRangeSet() {
    return CollectCollectors.toImmutableRangeSet();
  }

  /**

   */
  @SuppressWarnings({"AndroidJdkLibsChecker", "Java7ApiChecker"})
  @IgnoreJRERequirement // Users will use this only if they're already using streams.
  @Beta // TODO: b/288085449 - Remove.
  public static <T extends @Nullable Object, R, C, V>
      Collector<T, ?, ImmutableTable<R, C, V>> toImmutableTable(
          Function<? super T, ? extends R> rowFunction,

   */
  @SuppressWarnings({"AndroidJdkLibsChecker", "Java7ApiChecker"})
  @IgnoreJRERequirement // Users will use this only if they're already using streams.
  @Beta // TODO: b/288085449 - Remove.
  public static <T extends @Nullable Object, K, V>
      Collector<T, ?, ImmutableBiMap<K, V>> toImmutableBiMap(
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {

    assertTrue(cycle.hasNext());
    try {
      cycle.remove();
      fail("no exception thrown");
    } catch (IllegalStateException expected) {
    }
  }

  public void testCycleRemoveSameElementTwice() {
    Iterator<String> cycle = Iterators.cycle("a", "b");
    cycle.next();
    cycle.remove();
    try {
      cycle.remove();
      fail("no exception thrown");

@GwtCompatible
@ElementTypesAreNonnullByDefault
@SuppressWarnings({"AndroidJdkLibsChecker", "Java7ApiChecker"})
@IgnoreJRERequirement // Users will use this only if they're already using streams.
@Beta // TODO: b/288085449 - Remove.
public final class MoreCollectors {

  /*
   * TODO(lowasser): figure out if we can convert this to a concurrent AtomicReference-based
   * collector without breaking j2cl?
   */

      contents.put(element, occurrences + contents.get(element));
      return this;
    }

    /**
     * Adds or removes the necessary occurrences of an element such that the element attains the
     * desired count.
     *
     * @param element the element to add or remove occurrences of
     * @param count the desired count of the element in this multiset
     * @return this {@code Builder} object

   */
  @SuppressWarnings({"AndroidJdkLibsChecker", "Java7ApiChecker"})
  @IgnoreJRERequirement // Users will use this only if they're already using streams.
  @Beta // TODO: b/288085449 - Remove.
  public static <T extends @Nullable Object, K, V>
      Collector<T, ?, ImmutableListMultimap<K, V>> toImmutableListMultimap(
          Function<? super T, ? extends K> keyFunction,

   */
  @SuppressWarnings({"AndroidJdkLibsChecker", "Java7ApiChecker"})
  @IgnoreJRERequirement // Users will use this only if they're already using streams.
  @Beta // TODO: b/288085449 - Remove.
  public static <E> Collector<E, ?, ImmutableList<E>> toImmutableList() {
    return CollectCollectors.toImmutableList();
  }

  /**