* read operations anyway:
     *
     * - All (unsynchronized) read operations must first read the "count" field, and should not
     * look at table entries if it is 0.
     *
     * - All (synchronized) write operations should write to the "count" field after structurally
     * changing any bin. The operations must not take any action that could even momentarily

      }
    }

    /**
     * Throws UnsupportedOperationException. A future version may support this operation. Then the
     * value for any given key will be the one that was last supplied in a {@code put} operation for
     * that key.
     *
     * @throws UnsupportedOperationException always
     * @since 31.1

      fail("IllegalArgumentException expected");
    } catch (IllegalArgumentException expected) {
    }

    // These results are all incorrect, but there's no way (short of iterating over the result)
    // to verify that with an arbitrary ordering or comparator.
    assertEquals(ImmutableSortedSet.of(2, 4), Sets.subSet(set, Range.atLeast(4)));

      return set;
    }

    /**
     * Guaranteed to throw an exception and leave the collection unmodified.
     *
     * @throws UnsupportedOperationException always
     * @deprecated Unsupported operation.
     */
    @CanIgnoreReturnValue
    @Deprecated
    @Override
    @DoNotCall("Always throws UnsupportedOperationException")
    public final boolean add(@ParametricNullness E e) {

    /** Performs a GAS operation on the {@link #waiters} field. */
    abstract Waiter gasWaiters(AbstractFuture<?> future, Waiter update);

    /** Performs a GAS operation on the {@link #listeners} field. */
    abstract Listener gasListeners(AbstractFuture<?> future, Listener update);

    /** Performs a CAS operation on the {@link #value} field. */

      }
    }

    /**
     * Throws UnsupportedOperationException. A future version may support this operation. Then the
     * value for any given key will be the one that was last supplied in a {@code put} operation for
     * that key.
     *
     * @throws UnsupportedOperationException always
     * @since 31.1

    mod.put(1, "one");
    mod.put(2, "two");
    mod.put(3, "three");

    BiMap<Number, String> unmod = Maps.<Number, String>unmodifiableBiMap(mod);

    /* No aliasing on inverse operations. */
    assertSame(unmod.inverse(), unmod.inverse());
    assertSame(unmod, unmod.inverse().inverse());

    /* Unmodifiable is a view. */
    mod.put(4, "four");

    mod.put(1, "one");
    mod.put(2, "two");
    mod.put(3, "three");

    BiMap<Number, String> unmod = Maps.<Number, String>unmodifiableBiMap(mod);

    /* No aliasing on inverse operations. */
    assertSame(unmod.inverse(), unmod.inverse());
    assertSame(unmod, unmod.inverse().inverse());

    /* Unmodifiable is a view. */
    mod.put(4, "four");

 * entries may be counted in {@link Cache#size}, but will never be visible to read or write
 * operations.
 *
 * <p>Certain cache configurations will result in the accrual of periodic maintenance tasks which
 * will be performed during write operations, or during occasional read operations in the absence of
 * writes. The {@link Cache#cleanUp} method of the returned cache will also perform maintenance, but

   * {@code factory}, and the multimap contents are all serializable.
   *
   * <p>The multimap is not threadsafe when any concurrent operations update the multimap, even if
   * {@code map} and the instances generated by {@code factory} are. Concurrent read operations will
   * work correctly. To allow concurrent update operations, wrap the multimap with a call to {@link
   * #synchronizedMultimap}.
   *