* returns the low 32 bits of the result.
   *
   * @since 14.0
   */
  public UnsignedInteger plus(UnsignedInteger val) {
    return fromIntBits(this.value + checkNotNull(val).value);
  }

  /**
   * Returns the result of subtracting this and {@code val}. If the result would be negative,
   * returns the low 32 bits of the result.
   *
   * @since 14.0
   */

  private static long shiftMix(long val) {
    return val ^ (val >>> 47);
  }

  /** Implementation of Hash128to64 from util/hash/hash128to64.h */
  @VisibleForTesting
  static long hash128to64(long high, long low) {
    long a = (low ^ high) * K3;
    a ^= a >>> 47;
    long b = (high ^ a) * K3;
    b ^= b >>> 47;
    b *= K3;
    return b;
  }

  /**

  private static long shiftMix(long val) {
    return val ^ (val >>> 47);
  }

  /** Implementation of Hash128to64 from util/hash/hash128to64.h */
  @VisibleForTesting
  static long hash128to64(long high, long low) {
    long a = (low ^ high) * K3;
    a ^= a >>> 47;
    long b = (high ^ a) * K3;
    b ^= b >>> 47;
    b *= K3;
    return b;
  }

  /**

    // Two differing invalid pairs.
    assertEquals("\uDCABdef", Strings.commonSuffix("abc\uDCAB\uDCABdef", "abc\uDCAC\uDCABdef"));
    // One orphan low surrogate.
    assertEquals("", Strings.commonSuffix("x\uD8AB\uDCAB", "\uDCAB"));
    // Two orphan low surrogates.
    assertEquals("\uDCAB", Strings.commonSuffix("\uDCAB", "\uDCAB"));
  }

  public void testValidSurrogatePairAt() {

    // If anyone in our monorepo uses the Android copy of Guava on a JVM, that would be unfortunate.
    // But that is only likely to happen in Robolectric tests, where the risks of JDK regex are low.
    return new JdkPatternCompiler();
  }

  private static final class JdkPatternCompiler implements PatternCompiler {
    @Override
    public CommonPattern compile(String pattern) {

 *
 * <p>This class is usually preferable to {@link AtomicLong} when multiple threads update a common
 * sum that is used for purposes such as collecting statistics, not for fine-grained synchronization
 * control. Under low update contention, the two classes have similar characteristics. But under
 * high contention, expected throughput of this class is significantly higher, at the expense of
 * higher space consumption.
 *

   * which the superconstructor calls.
   */

  /**
   * Contains the link pointers corresponding with the entries, in the range of [0, size()). The
   * high 32 bits of each long is the "prev" pointer, whereas the low 32 bits is the "succ" pointer
   * (pointing to the nextEntry entry in the linked list). The pointers in [size(), entries.length)
   * are all "null" (UNSET).
   *

 *
 * @author Jared Levy
 * @since 2.0
 */
@GwtCompatible
@J2ktIncompatible
@SuppressWarnings("EnumOrdinal") // This is one of the low-level utilities where it's suitable.
public final class EnumMultiset<E extends Enum<E>> extends AbstractMultiset<E>
    implements Serializable {
  /** Creates an empty {@code EnumMultiset}. */

import static java.lang.Character.MAX_SURROGATE;
import static java.lang.Character.MIN_SURROGATE;

import com.google.common.annotations.GwtCompatible;

/**
 * Low-level, high-performance utility methods related to the {@linkplain Charsets#UTF_8 UTF-8}
 * character encoding. UTF-8 is defined in section D92 of <a
 * href="http://www.unicode.org/versions/Unicode6.2.0/ch03.pdf">The Unicode Standard Core

        .withFeatures(features)
        .suppressing(parentBuilder.getSuppressedTests())
        .createTestSuite();
  }

  /**
   * Returns an array of four bogus elements that will always be too high or too low for the
   * display. This includes two values for each extreme.
   *
   * <p>This method (dangerously) assume that the strings {@code "!! a"} and {@code "~~ z"} will