import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A mutable class-to-instance map backed by an arbitrary user-provided map. See also {@link
 * ImmutableClassToInstanceMap}.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#classtoinstancemap">{@code
 * ClassToInstanceMap}</a>.
 *
 * @author Kevin Bourrillion
 * @since 2.0
 */
@J2ktIncompatible

import javax.annotation.CheckForNull;

/**
 * Multiset implementation specialized for enum elements, supporting all single-element operations
 * in O(1).
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#multiset">{@code Multiset}</a>.
 *
 * @author Jared Levy
 * @since 2.0
 */
@GwtCompatible(emulated = true)
@J2ktIncompatible

 * be as expected on discrete ranges. See the Javadoc of those methods for details.
 *
 * <p>For a {@link Set} whose contents are specified by a {@link Range}, see {@link ContiguousSet}.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#rangeset">RangeSets</a>.
 *
 * @author Kevin Bourrillion
 * @author Louis Wasserman
 * @since 14.0
 */

 *
 * <p>Note that this implementation is not synchronized. If multiple threads access this table
 * concurrently and one of the threads modifies the table, it must be synchronized externally.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#table">{@code Table}</a>.
 *
 * @author Jared Levy
 * @author Louis Wasserman
 * @since 7.0
 */
@GwtCompatible(serializable = true)

/**
 * A {@link Table} whose contents will never change, with many other important properties detailed
 * at {@link ImmutableCollection}.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/ImmutableCollectionsExplained">immutable collections</a>.
 *
 * @author Gregory Kick
 * @since 11.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

 * 256 + b}). The corresponding methods that treat the values as signed are found in {@link
 * SignedBytes}, and the methods for which signedness is not an issue are in {@link Bytes}.
 *
 * <p>See the Guava User Guide article on <a
 * href="https://github.com/google/guava/wiki/PrimitivesExplained">primitive utilities</a>.
 *
 * @author Kevin Bourrillion
 * @author Martin Buchholz
 * @author Hiroshi Yamauchi
 * @author Louis Wasserman

---
title: "Go, Backwards Compatibility, and GODEBUG"
layout: article
---

<!--
This document is kept in the Go repo, not x/website,
because it documents the full list of known GODEBUG settings,
which are tied to a specific release.
-->

## Introduction {#intro}

Go's emphasis on backwards compatibility is one of its key strengths.
There are, however, times when we cannot maintain complete compatibility.

 *
 * <p><b>There are no plans to deprecate this class in the foreseeable future.</b> However, we do
 * gently recommend that you prefer the new, standard Java class whenever possible.
 *
 * <p>See the Guava User Guide article on <a
 * href="https://github.com/google/guava/wiki/UsingAndAvoidingNullExplained#optional">using {@code
 * Optional}</a>.
 *
 * @param <T> the type of instance that can be contained. {@code Optional} is naturally covariant on

   *       traffic to {@code charlie}, rather than letting {@code bravo} keep its traffic.
   * </ul>
   *
   * <p>See the <a href="http://en.wikipedia.org/wiki/Consistent_hashing">Wikipedia article on
   * consistent hashing</a> for more information.
   */
  public static int consistentHash(HashCode hashCode, int buckets) {
    return consistentHash(hashCode.padToLong(), buckets);
  }

  /**

/**
 * A multiset that supports concurrent modifications and that provides atomic versions of most
 * {@code Multiset} operations (exceptions where noted). Null elements are not supported.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#multiset">{@code Multiset}</a>.
 *
 * @author Cliff L. Biffle
 * @author mike nonemacher
 * @since 2.0
 */
@J2ktIncompatible