* maps ("constant maps"). Example:
   *
   * <pre>{@code
   * static final ImmutableSortedMap<Integer, String> INT_TO_WORD =
   *     new ImmutableSortedMap.Builder<Integer, String>(Ordering.natural())
   *         .put(1, "one")
   *         .put(2, "two")
   *         .put(3, "three")
   *         .buildOrThrow();
   * }</pre>
   *

   * cast, for example:
   *
   * <pre>{@code
   * Set<Object> aFewBadObjects = ...
   * Set<String> manyBadStrings = ...
   *
   * // impossible for a non-String to be in the intersection
   * SuppressWarnings("unchecked")
   * Set<String> badStrings = (Set) Sets.intersection(
   *     aFewBadObjects, manyBadStrings);
   * }</pre>
   *

    assertTrue(Arrays.equals(new String[] {"a"}, array));
  }

  @GwtIncompatible // Iterators.toArray(Iterator, Class)
  public void testToArray() {
    String[] sourceArray = new String[] {"a", "b", "c"};
    Iterator<String> iterator = asList(sourceArray).iterator();
    String[] newArray = Iterators.toArray(iterator, String.class);
    assertTrue(Arrays.equals(sourceArray, newArray));
  }

   *
   * <pre>{@code
   * Multimap<String, Integer> multimap =
   *     ImmutableMultimap.of("a", 1, "a", 4, "b", 6);
   * EntryTransformer<String, Integer, String> transformer =
   *     new EntryTransformer<String, Integer, String>() {
   *       public String transformEntry(String key, Integer value) {
   *         return key + value;
   *       }
   *     };
   * Multimap<String, String> transformed =

   * guaranteed to return the same object again. For example:
   *
   * <pre>{@code
   * PeekingIterator<String> peekingIterator =
   *     Iterators.peekingIterator(Iterators.forArray("a", "b"));
   * String a1 = peekingIterator.peek(); // returns "a"
   * String a2 = peekingIterator.peek(); // also returns "a"
   * String a3 = peekingIterator.next(); // also returns "a"
   * }</pre>
   *