}

  /**
   * Not supported. Use {@link #toImmutableBiMap} instead. This method exists only to hide {@link
   * ImmutableMap#toImmutableMap(Function, Function)} from consumers of {@code ImmutableBiMap}.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Use {@link ImmutableBiMap#toImmutableBiMap}.
   */
  @Deprecated
  @DoNotCall("Use toImmutableBiMap")
  public static <T extends @Nullable Object, K, V>

  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) {
    return CollectCollectors.toImmutableBiMap(keyFunction, valueFunction);
  }

  /**
   * Returns the empty bimap.
   *

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.collect.ImmutableBiMap.toImmutableBiMap;
import static com.google.common.collect.Maps.immutableEntry;
import static com.google.common.collect.ReflectionFreeAssertThrows.assertThrows;
import static com.google.common.collect.Sets.newHashSet;

        ImmutableSortedMap::copyOfSorted);
  }

  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) {
    checkNotNull(keyFunction);
    checkNotNull(valueFunction);
    return Collector.of(