return MoreObjects.firstNonNull(asMap().remove(key), unmodifiableEmptyCollection());
  }

  Collection<V> unmodifiableEmptyCollection() {
    // These return false, rather than throwing a UOE, on remove calls.
    return (unfiltered instanceof SetMultimap)
        ? Collections.<V>emptySet()
        : Collections.<V>emptyList();
  }

  @Override
  public void clear() {
    entries().clear();
  }

    WeakReference<?> classUsedByGetChecked = doTestClassUnloading();
    GcFinalization.awaitClear(classUsedByGetChecked);
  }

  /**
   * Loads {@link WillBeUnloadedException} in a separate {@code ClassLoader}, calls {@code
   * getChecked(future, WillBeUnloadedException.class)}, and returns the loader. The caller can then
   * test that the {@code ClassLoader} can still be GCed. The test amounts to a test that {@code

    return new JavaIoCreator();
  }

  /**
   * Creates the permissions normally used for Windows filesystems, looking up the user afresh, even
   * if previous calls have initialized the {@code PermissionSupplier} fields.
   *
   * <p>This lets us test the effects of different values of the {@code user.name} system property
   * without needing a separate VM or classloader.
   */

            throw new ServletException("Failed to initialize CIFS context");
        }
    }


    @Override
    public void destroy () {}


    /**
     * This method simply calls <tt>negotiate( req, resp, false )</tt>
     * and then <tt>chain.doFilter</tt>. You can override and call
     * negotiate manually to achive a variety of different behavior.
     */
    @Override

   * were obtained by calling {@code snapshot()} on the same {@link PairedStatsAccumulator} without
   * adding any values in between the two calls, or if one is obtained from the other after
   * round-tripping through java serialization. However, floating point rounding errors mean that it

      if (!firstTimeSeen) {
        /*
         * We've seen this, so we've seen its causes, too. No need to re-add them. (There's one case
         * where this isn't true, but we ignore it: If we record an exception, then someone calls
         * initCause() on it, and then we examine it again, we'll conclude that we've seen the whole
         * chain before when in fact we haven't. But this should be rare.)
         */
        return false;
      }

    /**
     * Wraps an arbitrary object with an {@link ObjectBasedValueSource} instance, then
     * wraps that source with a {@link PrefixedValueSourceWrapper} instance, to which
     * this class delegates all of its calls.
     */
    public static class PrefixedObjectValueSource extends AbstractDelegatingValueSource
            implements QueryEnabledValueSource {

        /**

    InternetDomainName parent = origin.parent();
    assertEquals("com", parent.toString());

    // These would throw an exception if leniency were not preserved during parent() and child()
    // calls.
    InternetDomainName child = parent.child(LOTS_OF_DELTAS);
    InternetDomainName unused = child.child(LOTS_OF_DELTAS);
  }

  public void testValidTopPrivateDomain() {

    // Service b startup takes at least 353 millis, but starting the timer is delayed by at least
    // 150 milliseconds. so in a perfect world the timing would be 353-150=203ms, but since either
    // of our sleep calls can be arbitrarily delayed we should just assert that there is a time
    // recorded.
    assertThat(startupTimes.get(b)).isNotNull();
  }

  public void testServiceStartStop() {
    Service a = new NoOpService();

public class StreamsTest extends TestCase {
  /*
   * Full and proper black-box testing of a Stream-returning method is extremely involved, and is
   * overkill when nearly all Streams are produced using well-tested JDK calls. So, we cheat and
   * just test that the toArray() contents are as expected.
   */
  public void testStream_nonCollection() {
    assertThat(stream(FluentIterable.of())).isEmpty();