public static final String X_FORWARDED_PROTO = "X-Forwarded-Proto";
  /**
   * The HTTP <a href="http://goo.gl/lQirAH">{@code X-Forwarded-Host}</a> header field name.
   *
   * @since 20.0
   */
  public static final String X_FORWARDED_HOST = "X-Forwarded-Host";
  /**
   * The HTTP <a href="http://goo.gl/YtV2at">{@code X-Forwarded-Port}</a> header field name.
   *
   * @since 20.0
   */

   *
   * <p><b>Note:</b> this method is now unnecessary and should be treated as deprecated. Instead,
   * use the {@code HashMap} constructor directly, taking advantage of <a
   * href="http://goo.gl/iz2Wi">"diamond" syntax</a>.
   *
   * @return a new, empty {@code HashMap}
   */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      HashMap<K, V> newHashMap() {

      };

  /**
   * Returns a new {@code MatchResult} that corresponds to a successful match. Apache Harmony (used
   * in Android) requires a successful match in order to generate a {@code MatchResult}:
   * http://goo.gl/5VQFmC
   */
  private static MatchResult createMatchResult() {
    Matcher matcher = Pattern.compile(".").matcher("X");
    matcher.find();
    return matcher.toMatchResult();
  }

      };

  /**
   * Returns a new {@code MatchResult} that corresponds to a successful match. Apache Harmony (used
   * in Android) requires a successful match in order to generate a {@code MatchResult}:
   * http://goo.gl/5VQFmC
   */
  private static MatchResult createMatchResult() {
    Matcher matcher = Pattern.compile(".").matcher("X");
    matcher.find();
    return matcher.toMatchResult();
  }

/**
 * Static methods to obtain {@link HashFunction} instances, and other static hashing-related
 * utilities.
 *
 * <p>A comparison of the various hash functions can be found <a
 * href="http://goo.gl/jS7HH">here</a>.
 *
 * @author Kevin Bourrillion
 * @author Dimitris Andreou
 * @author Kurt Alfred Kluever
 * @since 11.0
 */
@ElementTypesAreNonnullByDefault
public final class Hashing {
  /**