toRemove = mapEntry;
        return mapEntry.getKey();
      }

      @Override
      public void remove() {
        checkState(toRemove != null, "no calls to next() since the last call to remove()");
        size -= toRemove.getValue().getAndSet(0);
        backingEntries.remove();
        toRemove = null;
      }
    };
  }

  @Override

import java.util.NavigableSet;
import java.util.SortedSet;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A navigable set which forwards all its method calls to another navigable set. Subclasses should
 * override one or more methods to modify the behavior of the backing set as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *

import java.util.Iterator;
import java.util.NavigableSet;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A sorted multiset which forwards all its method calls to another sorted multiset. Subclasses
 * should override one or more methods to modify the behavior of the backing multiset as desired per
 * the <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *

   * Returns whether the source has zero bytes. The default implementation first checks {@link
   * #sizeIfKnown}, returning true if it's known to be zero and false if it's known to be non-zero.
   * If the size is not known, it falls back to opening a stream and checking for EOF.
   *
   * <p>Note that, in cases where {@code sizeIfKnown} returns zero, it is <i>possible</i> that bytes

  /**
   * Chooses and returns the representative instance for any of a collection of instances that are
   * equal to each other. If two {@linkplain Object#equals equal} inputs are given to this method,
   * both calls will return the same instance. That is, {@code intern(a).equals(a)} always holds,
   * and {@code intern(a) == intern(b)} if and only if {@code a.equals(b)}. Note that {@code

import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

/**
 * A {@link Future} implementation which always throws directly from calls to {@code get()} (i.e.
 * not wrapped in {@code ExecutionException}. For just a normal failure, use {@link
 * SettableFuture}).
 *
 * <p>Useful for testing the behavior of Future utilities against odd futures.
 *

import com.google.common.collect.ImmutableMap;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.concurrent.ExecutionException;

/**
 * A cache which forwards all its method calls to another cache. Subclasses should override one or
 * more methods to modify the behavior of the backing cache as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *

    }
  }

  @Override
  public Hasher newHasher() {
    if (supportsClone) {
      try {
        return new MacHasher((Mac) prototype.clone());
      } catch (CloneNotSupportedException e) {
        // falls through
      }
    }
    return new MacHasher(getMac(prototype.getAlgorithm(), key));
  }

  @Override
  public String toString() {
    return toString;
  }

   * That is, the first call to {@link #nextIndex()} will return {@code position}, and the first
   * call to {@link #next()} will return the element at that index, if available. Calls to {@link
   * #previous()} can retrieve the preceding {@code position} elements.
   *
   * @throws IndexOutOfBoundsException if {@code position} is negative or is greater than {@code
   *     size}

import java.util.Collection;
import java.util.Map;
import java.util.Set;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A table which forwards all its method calls to another table. Subclasses should override one or
 * more methods to modify the behavior of the backing map as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *