if (atomic == null) {
      return 0L;
    }

    while (true) {
      long oldValue = atomic.get();
      if (oldValue == 0L || atomic.compareAndSet(oldValue, 0L)) {
        // only remove after setting to zero, to avoid concurrent updates
        map.remove(key, atomic);
        // succeed even if the remove fails, since the value was already adjusted
        return oldValue;
      }
    }
  }

  GENERAL_PURPOSE(
      CollectionFeature.GENERAL_PURPOSE,
      SUPPORTS_SET,
      SUPPORTS_ADD_WITH_INDEX,
      SUPPORTS_REMOVE_WITH_INDEX),

  /** Features supported by lists where only removal is allowed. */
  REMOVE_OPERATIONS(CollectionFeature.REMOVE_OPERATIONS, SUPPORTS_REMOVE_WITH_INDEX);

  private final Set<Feature<? super List>> implied;

  ListFeature(Feature<? super List>... implied) {

import com.google.common.testing.EqualsTester;
import org.junit.Ignore;

/**
 * Testers for {@link ListMultimap#equals(Object)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class ListMultimapEqualsTester<K, V> extends AbstractListMultimapTester<K, V> {

import java.util.List;
import java.util.Set;
import org.junit.Ignore;

/**
 * Tests for {@link SetMultimap#replaceValues}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class SetMultimapPutAllTester<K, V> extends AbstractMultimapTester<K, V, SetMultimap<K, V>> {

import java.util.List;
import org.junit.Ignore;

/**
 * Tests for {@link SetMultimap#replaceValues}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class SetMultimapReplaceValuesTester<K, V>
    extends AbstractMultimapTester<K, V, SetMultimap<K, V>> {

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Signifies that a test should not be run under Android. This annotation is respected only by our
 * Google-internal Android suite generators. Note that those generators also suppress any test
 * annotated with MediumTest or LargeTest.
 *

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Signifies that a test should not be run under Android. This annotation is respected only by our
 * Google-internal Android suite generators. Note that those generators also suppress any test
 * annotated with MediumTest or LargeTest.
 *

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Signifies that a test should not be run under Android. This annotation is respected only by our
 * Google-internal Android suite generators. Note that those generators also suppress any test
 * annotated with MediumTest or LargeTest.
 *

     *
     * @return the assembled settings, never {@code null}
     */
    @Nonnull
    Settings getEffectiveSettings();

    /**
     * Gets the problems that were encountered during the settings building. Note that only problems of severity
     * {@link BuilderProblem.Severity#WARNING} and below are reported here. Problems with a higher severity level cause
     * the settings builder to fail with a {@link SettingsBuilderException}.
     *

     */
    @Nonnull
    PersistedToolchains getEffectiveToolchains();

    /**
     * Gets the problems that were encountered during the settings building. Note that only problems of severity
     * {@link BuilderProblem.Severity#WARNING} and below are reported here. Problems with a higher severity level cause
     * the settings builder to fail with a {@link ToolchainsBuilderException}.
     *