* elements will appear in the returned list in the same order they appeared in {@code elements}.
   *
   * <p><b>Performance note:</b> According to our
   * benchmarking
   * on Open JDK 7, this method is the most efficient way to make a sorted copy of a collection.
   *
   * @throws NullPointerException if any element of {@code elements} is {@code null}
   * @since 3.0
   */
  // TODO(kevinb): rerun benchmarks including new options

    assertEquals("", is('a').retainFrom(""));
  }

  public void testPrecomputedOptimizations() {
    // These are testing behavior that's never promised by the API.
    // Some matchers are so efficient that it is a waste of effort to
    // build a precomputed version.
    CharMatcher m1 = is('x');
    assertSame(m1, m1.precomputed());
    assertEquals(m1.toString(), m1.precomputed().toString());

  }

  /**
   * Creates an empty multiset containing the given initial elements, sorted according to the
   * elements' natural order.
   *
   * <p>This implementation is highly efficient when {@code elements} is itself a {@link Multiset}.
   *
   * <p>The type specification is {@code <E extends Comparable>}, instead of the more specific

  // +optional
  optional GroupVersionForDiscovery preferredVersion = 3;

  // a map of client CIDR to server address that is serving this group.
  // This is to help clients reach servers in the most network-efficient way possible.
  // Clients can use the appropriate server address as per the CIDR that they match.
  // In case of multiple matches, clients should use the longest matching CIDR.

 *
 * This is because those two hosts share the same IP address. This is an old, bad design decision
 * that makes `java.net.URL` unusable for many things. It shouldn't be used as a [Map] key or in a
 * [Set]. Doing so is both inefficient because equality may require a DNS lookup, and incorrect
 * because unequal URLs may be equal because of how they are hosted.
 *
 * ### Equal URLs should be equal
 *

### Synchronous Get ([.kt][SynchronousGetKotlin], [.java][SynchronousGetJava])

Download a file, print its headers, and print its response body as a string.

The `string()` method on response body is convenient and efficient for small documents. But if the response body is large (greater than 1 MiB), avoid `string()` because it will load the entire document into memory. In that case, prefer to process the body as a stream.

   * is as close as possible to the center of the range [{@code from}, {@code to}]. Choosing the
   * value closest to the center of the range first is the most efficient strategy because it
   * minimizes the size of the subranges from which the remaining selections must be done.
   */
  private static int chooseNextSelection(

  /** The concurrency level. */
  final int concurrencyLevel;

  /** Strategy for comparing keys. */
  final Equivalence<Object> keyEquivalence;

  /** Strategy for handling entries and segments in a type-safe and efficient manner. */
  final transient InternalEntryHelper<K, V, E, S> entryHelper;

  /**
   * Creates a new, empty map with the specified strategy, initial capacity and concurrency level.
   */

  /** The concurrency level. */
  final int concurrencyLevel;

  /** Strategy for comparing keys. */
  final Equivalence<Object> keyEquivalence;

  /** Strategy for handling entries and segments in a type-safe and efficient manner. */
  final transient InternalEntryHelper<K, V, E, S> entryHelper;

  /**
   * Creates a new, empty map with the specified strategy, initial capacity and concurrency level.
   */

   * elements will appear in the returned list in the same order they appeared in {@code elements}.
   *
   * <p><b>Performance note:</b> According to our
   * benchmarking
   * on Open JDK 7, this method is the most efficient way to make a sorted copy of a collection.
   *
   * @throws NullPointerException if any element of {@code elements} is {@code null}
   * @since 3.0
   */
  // TODO(kevinb): rerun benchmarks including new options