MapMaker builder) {
    if (builder.getKeyStrength() == Strength.STRONG
        && builder.getValueStrength() == Strength.STRONG) {
      return new MapMakerInternalMap<>(builder, StrongKeyStrongValueEntry.Helper.<K, V>instance());
    }
    if (builder.getKeyStrength() == Strength.STRONG
        && builder.getValueStrength() == Strength.WEAK) {

import static org.junit.Assert.assertThrows;

import com.google.common.base.Function;
import com.google.common.collect.Interners.InternerImpl;
import com.google.common.collect.MapMakerInternalMap.Strength;
import com.google.common.testing.GcFinalization;
import com.google.common.testing.NullPointerTester;
import java.lang.ref.WeakReference;
import junit.framework.TestCase;

/**
 * Unit test for {@link Interners}.

    assertEquals(20, spec.maximumSize.intValue());
    assertNull(spec.maximumWeight);
    assertEquals(30, spec.concurrencyLevel.intValue());
    assertEquals(Strength.WEAK, spec.keyStrength);
    assertEquals(Strength.WEAK, spec.valueStrength);
    assertEquals(HOURS, spec.writeExpirationTimeUnit);
    assertEquals(MINUTES, spec.accessExpirationTimeUnit);
    assertEquals(1L, spec.writeExpirationDuration);

        }
      };

  private CacheBuilderFactory factoryWithAllKeyStrengths() {
    return new CacheBuilderFactory()
        .withKeyStrengths(ImmutableSet.of(STRONG, Strength.WEAK))
        .withValueStrengths(ImmutableSet.of(STRONG, Strength.WEAK, Strength.SOFT));
  }

  private Iterable<LoadingCache<Key, String>> caches() {
    CacheBuilderFactory factory = factoryWithAllKeyStrengths();
    return Iterables.transform(

   * @throws IllegalStateException if the key strength was already set
   */
  @GwtIncompatible // java.lang.ref.WeakReference
  @CanIgnoreReturnValue
  public CacheBuilder<K, V> weakKeys() {
    return setKeyStrength(Strength.WEAK);
  }

  @CanIgnoreReturnValue
  CacheBuilder<K, V> setKeyStrength(Strength strength) {
    checkState(keyStrength == null, "Key strength was already set to %s", keyStrength);

      MapMaker builder) {
    if (builder.getKeyStrength() == Strength.STRONG
        && builder.getValueStrength() == Strength.STRONG) {
      return new MapMakerInternalMap<>(builder, StrongKeyStrongValueEntry.Helper.<K, V>instance());
    }
    if (builder.getKeyStrength() == Strength.STRONG
        && builder.getValueStrength() == Strength.WEAK) {

    assertEquals(20, spec.maximumSize.intValue());
    assertNull(spec.maximumWeight);
    assertEquals(30, spec.concurrencyLevel.intValue());
    assertEquals(Strength.WEAK, spec.keyStrength);
    assertEquals(Strength.WEAK, spec.valueStrength);
    assertEquals(HOURS, spec.writeExpirationTimeUnit);
    assertEquals(MINUTES, spec.accessExpirationTimeUnit);
    assertEquals(1L, spec.writeExpirationDuration);

   * @throws IllegalStateException if the key strength was already set
   */
  @GwtIncompatible // java.lang.ref.WeakReference
  @CanIgnoreReturnValue
  public CacheBuilder<K, V> weakKeys() {
    return setKeyStrength(Strength.WEAK);
  }

  @CanIgnoreReturnValue
  CacheBuilder<K, V> setKeyStrength(Strength strength) {
    checkState(keyStrength == null, "Key strength was already set to %s", keyStrength);

import static org.junit.Assert.assertThrows;

import com.google.common.base.Function;
import com.google.common.collect.Interners.InternerImpl;
import com.google.common.collect.MapMakerInternalMap.Strength;
import com.google.common.testing.GcFinalization;
import com.google.common.testing.NullPointerTester;
import java.lang.ref.WeakReference;
import junit.framework.TestCase;

/**
 * Unit test for {@link Interners}.

    // would cause one to be evicted.
    return new CacheBuilderFactory()
        .withKeyStrengths(ImmutableSet.of(Strength.STRONG, Strength.WEAK))
        .withValueStrengths(ImmutableSet.copyOf(Strength.values()))
        .withConcurrencyLevels(ImmutableSet.of(1, 4, 16, 64))
        .withMaximumSizes(ImmutableSet.of(400, 1000))