builder.addEscape(' ', "_");
    Escaper first = builder.build();
    // Modify one of the existing mappings before creating a new escaper.
    builder.addEscape(' ', "-");
    builder.addEscape('!', "$");
    Escaper second = builder.build();
    // This should have no effect on existing escapers.
    builder.addEscape(' ', "*");

    // Test both escapers after modifying the builder.

   */
  @CanIgnoreReturnValue
  @Override
  @CheckForNull
  V put(@ParametricNullness K key, @ParametricNullness V value);

  /**
   * An alternate form of {@code put} that silently removes any existing entry with the value {@code
   * value} before proceeding with the {@link #put} operation. If the bimap previously contained the
   * provided key-value mapping, this method has no effect.
   *

 */

package com.google.common.collect.testing;

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;

/**
 * Suite of tests for OpenJdk 6 tests. The existence of this class is a hack because the
 * suitebuilder won't pick up the suites directly in the other classes because they don't extend
 * TestCase. Ergh.
 *
 * @author Kevin Bourrillion
 */

 * requirement that existing callers already fulfill).
 *
 * Disclaimer: Part of the reason that callers are so well adapted to `Function<A, B>` may be that
 * that is how the signature looked even prior to this comment! So naturally any change can break
 * existing users, but it can't *fix* existing users because any users who needed

   *
   * <p>The {@link OutputStream} should not be written to before or after the hand-off.
   */
  // TODO(user): Evaluate whether it makes sense to always piggyback the computation of a
  // HashCode on an existing OutputStream, compared to creating a separate OutputStream that could
  // be (optionally) be combined with another if needed (with something like
  // MultiplexingOutputStream).

 *
 * <p><b>{@code default} method warning:</b> This class forwards calls to <i>only some</i> {@code
 * default} methods. Specifically, it forwards calls only for methods that existed <a
 * href="https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ConcurrentMap.html">before
 * {@code default} methods were introduced</a>. For newer methods, like {@code forEach}, it inherits

  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutIfAbsent_supportedPresent() {
    assertEquals(
        "putIfAbsent(present, value) should return existing value",
        v0(),
        getMap().putIfAbsent(k0(), v3()));
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testPutIfAbsent_unsupportedAbsent() {
    try {

  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutIfAbsent_supportedPresent() {
    assertEquals(
        "putIfAbsent(present, value) should return existing value",
        v0(),
        getMap().putIfAbsent(k0(), v3()));
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testPutIfAbsent_unsupportedAbsent() {
    try {

  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testComputeIfAbsent_supportedPresent() {
    assertEquals(
        "computeIfAbsent(present, function) should return existing value",
        v0(),
        getMap()
            .computeIfAbsent(
                k0(),
                k -> {
                  throw new AssertionFailedError();
                }));
    expectUnchanged();

 * operations at random. Each thread keeps track of the per-key deltas that it's directly
 * responsible for; after all threads have completed, we sum the per-key deltas and compare to the
 * existing multiset values.
 *
 * @author mike nonemacher
 */

public class ConcurrentHashMultisetBasherTest extends TestCase {

  public void testAddAndRemove_ConcurrentHashMap() throws Exception {