public enum Modifiability {
    NONE, // immutable lists
    BY_ELEMENT, // elements can change (set), but not structure
    DIRECT_ONLY, // Element can be added and removed only via direct calls, not through iterators
    ALL // Elements can be added and removed as well as modified.
  }

  /** Handles the creation of lists needed for the tests */
  public abstract static class ListExample {

    private final String name;

   */
  public static <E> Builder<E> builder() {
    return new Builder<>();
  }

  /**
   * Returns a new builder, expecting the specified number of elements to be added.
   *
   * <p>If {@code expectedSize} is exactly the number of elements added to the builder before {@link
   * Builder#build} is called, the builder is likely to perform better than an unsized {@link
   * #builder()} would have.
   *

    }

    /**
     * Adds {@code element} to the {@code ImmutableSortedSet}. If the {@code ImmutableSortedSet}
     * already contains {@code element}, then {@code add} has no effect. (only the previously added
     * element is retained).
     *
     * @param element the element to add
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code element} is null
     */

    ImmutableSet<String> set = this.<String>builder().addAll(a).addAll(b).build();
    assertThat(set).containsExactly("a", "b", "c", "d", "e").inOrder();
  }

  static final int LAST_COLOR_ADDED = 0x00BFFF;

  public void testComplexBuilder() {
    List<Integer> colorElem = asList(0x00, 0x33, 0x66, 0x99, 0xCC, 0xFF);
    // javac won't compile this without "this.<Integer>"

    ImmutableSet<String> set = this.<String>builder().addAll(a).addAll(b).build();
    assertThat(set).containsExactly("a", "b", "c", "d", "e").inOrder();
  }

  static final int LAST_COLOR_ADDED = 0x00BFFF;

  public void testComplexBuilder() {
    List<Integer> colorElem = asList(0x00, 0x33, 0x66, 0x99, 0xCC, 0xFF);
    // javac won't compile this without "this.<Integer>"

    Builder<K, V> combine(Builder<K, V> builder) {
      entries.addAll(builder.entries);
      return this;
    }

    /**
     * Returns an {@code ImmutableRangeMap} containing the associations previously added to this
     * builder.
     *
     * @throws IllegalArgumentException if any two ranges inserted into this builder overlap
     */
    public ImmutableRangeMap<K, V> build() {

   * following conditions:
   *
   * <ul>
   *   <li>You want to assign the same fraction of inputs to each bucket.
   *   <li>When you reduce the number of buckets, you can accept that the most recently added
   *       buckets will be removed first. More concretely, if you are dividing traffic among tasks,
   *       you can decrease the number of tasks from 15 and 10, killing off the final 5 tasks, and

   * inputs, with counts equal to the result of applying {@code countFunction} to the inputs.
   * Elements are added in encounter order.
   *
   * <p>If the mapped elements contain duplicates (according to {@link Object#equals}), the element
   * will be added more than once, with the count summed over all appearances of the element.
   *

   * will remember the first duplicate key we encountered. All later calls to buildOrThrow() can
   * mention that key with its values. Further duplicates might be added in the meantime but since
   * builders only ever accumulate entries it will always be valid to throw from buildOrThrow() with
   * the first duplicate.
   */

    List<String> alreadyThere = Lists.newArrayList("already", "there");
    List<String> freshlyAdded = Lists.newArrayList("freshly", "added");

    boolean changed = Iterators.addAll(alreadyThere, freshlyAdded.iterator());

    assertThat(alreadyThere).containsExactly("already", "there", "freshly", "added");
    assertTrue(changed);
  }

  public void testAddAllToSet() {