* limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.collect.ImmutableMultiset.toImmutableMultiset;
import static com.google.common.collect.Iterators.emptyIterator;
import static com.google.common.collect.Iterators.singletonIterator;
import static com.google.common.collect.ReflectionFreeAssertThrows.assertThrows;

  public static <E> Collector<E, ?, ImmutableMultiset<E>> toImmutableMultiset() {
    throw new UnsupportedOperationException();
  }

  /**
   * Not supported. Use {@link #toImmutableSortedMultiset} instead. This method exists only to hide
   * {@link ImmutableMultiset#toImmutableMultiset} from consumers of {@code
   * ImmutableSortedMultiset}.
   *

    return (Collector) TO_IMMUTABLE_RANGE_SET;
  }

  // Multisets

  static <T extends @Nullable Object, E> Collector<T, ?, ImmutableMultiset<E>> toImmutableMultiset(
      Function<? super T, ? extends E> elementFunction, ToIntFunction<? super T> countFunction) {
    checkNotNull(elementFunction);
    checkNotNull(countFunction);
    return Collector.of(

   *
   * <p><b>{@code Stream} equivalent:</b> {@code ImmutableMultiset.copyOf(stream.iterator())}, or
   * pass {@link ImmutableMultiset#toImmutableMultiset} to {@code stream.collect()}.
   *
   * @throws NullPointerException if any element is null
   * @since 19.0
   */
  @SuppressWarnings("nullness") // Unsafe, but we can't do much about it now.

   * {@code stream.map(function).collect(Collectors.toCollection(supplier))}.
   *
   * <p>To collect to an {@link ImmutableMultiset}, use {@link
   * ImmutableMultiset#toImmutableMultiset}.
   *
   * @since 33.2.0 (available since 22.0 in guava-jre)
   */
  @SuppressWarnings("Java7ApiChecker")
  @IgnoreJRERequirement // Users will use this only if they're already using streams.

   * {@code stream.map(function).collect(Collectors.toCollection(supplier))}.
   *
   * <p>To collect to an {@link ImmutableMultiset}, use {@link
   * ImmutableMultiset#toImmutableMultiset}.
   *
   * @since 22.0
   */
  public static <T extends @Nullable Object, E extends @Nullable Object, M extends Multiset<E>>
      Collector<T, ?, M> toMultiset(
          Function<? super T, E> elementFunction,