}

  private CacheBuilderFactory cacheFactory() {
    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(0, 1, 10, 100, 1000))

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.errorprone.annotations.concurrent.LazyInit;
import com.google.j2objc.annotations.RetainedWith;
import com.google.j2objc.annotations.Weak;
import com.google.j2objc.annotations.WeakOuter;
import java.io.Serializable;
import java.util.AbstractCollection;
import java.util.AbstractMap;
import java.util.AbstractMap.SimpleImmutableEntry;

      `I kept all my limbs very supple
    By the use of this ointment--one shilling the box--
      Allow me to sell you a couple?'

    `You are old,' said the youth, `and your jaws are too weak
      For anything tougher than suet;
    Yet you finished the goose, with the bones and the beak--
      Pray how did you manage to do it?'

    `In my youth,' said his father, `I took to the law,

      `I kept all my limbs very supple
    By the use of this ointment--one shilling the box--
      Allow me to sell you a couple?'

    `You are old,' said the youth, `and your jaws are too weak
      For anything tougher than suet;
    Yet you finished the goose, with the bones and the beak--
      Pray how did you manage to do it?'

    `In my youth,' said his father, `I took to the law,