* "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the

 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the

 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the

 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the

 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the

 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the

   * Returns a builder that creates immutable sorted sets whose elements are ordered by the reverse
   * of their natural ordering.
   */
  public static <E extends Comparable<?>> Builder<E> reverseOrder() {
    return new Builder<>(Collections.reverseOrder());
  }

  /**
   * Returns a builder that creates immutable sorted sets whose elements are ordered by their

   * elements. The generated map is sorted by the specified comparator.
   *
   * <p>If the mapped keys contain duplicates (according to the specified comparator), an {@code
   * IllegalArgumentException} is thrown when the collection operation is performed. (This differs
   * from the {@code Collector} returned by {@link Collectors#toMap(Function, Function)}, which
   * throws an {@code IllegalStateException}.)

     * the associated element if the associated count is one, and otherwise the associated element
     * followed by the characters " x " (space, x and space) followed by the count. Elements and
     * counts are converted to strings as by {@code String.valueOf}.
     */
    @Override
    public String toString() {
      String text = String.valueOf(getElement());
      int n = getCount();

  }

  /**
   * Combines four iterables into a single iterable. The returned iterable has an iterator that
   * traverses the elements in {@code a}, followed by the elements in {@code b}, followed by the
   * elements in {@code c}, followed by the elements in {@code d}. The source iterators are not
   * polled until necessary.
   *
   * <p>The returned iterable's iterator supports {@code remove()} when the corresponding input