* checkNotNull *should* be annotated to require it to be non-null.
   *
   * However, for a variety of reasons, Google developers have written a ton of code over the past
   * decade that assumes that they can use checkNotNull for non-precondition checks. I had hoped to
   * take a principled stand on this, but the amount of such code is simply overwhelming. To avoid

   *
   * <p>Despite the method name, this method attempts to avoid actually copying the data when it is
   * safe to do so. The exact circumstances under which a copy will or will not be performed are
   * undocumented and subject to change.
   *
   * @throws NullPointerException if any key or value in {@code map} is null
   * @throws IllegalArgumentException if any two keys are equal according to the comparator
   */

  /**
   * Test-helper method that performs {@code nThreads} concurrent calls to {@code cache.get(key)} or
   * {@code cache.getUnchecked(key)}, and returns a List containing each of the results. The result
   * for any given call to {@code cache.get} or {@code cache.getUnchecked} is the value returned, or
   * the exception thrown.
   *
   * <p>As we iterate from {@code 0} to {@code nThreads}, threads with an even index will call

  }

  private static <E> List<E> list(E... elements) {
    return ImmutableList.copyOf(elements);
  }

  /**
   * Utility method to verify that the given LinkedHashSet is equal to and hashes identically to a
   * set constructed with the elements in the given collection. Also verifies that the ordering in
   * the set is the same as the ordering of the given contents.
   */

    } catch (NullPointerException e) {
    }
    try {
      result.next();
      fail("no exception thrown");
    } catch (NullPointerException e) {
    }
    // There is no way to get "through" to the 3.  Buh-bye
  }

  public void testConcatVarArgsContainingNull() {
    try {
      Iterators.concat(iterateOver(1, 2), null, iterateOver(3), iterateOver(4), iterateOver(5));

   * method is invoked automatically by a successful call to {@link #cancel(boolean) cancel(true)}.
   *
   * <p>The default implementation does nothing.
   *
   * <p>This method is likely to be deprecated. Prefer to override {@link #afterDone}, consulting
   * {@link #wasInterrupted} to decide whether to interrupt your task.
   *
   * @since 10.0
   */
  protected void interruptTask() {}

  /**

   *
   * <p>Despite the method name, this method attempts to avoid actually copying the data when it is
   * safe to do so. The exact circumstances under which a copy will or will not be performed are
   * undocumented and subject to change.
   *
   * @throws NullPointerException if any key or value in {@code map} is null
   * @throws IllegalArgumentException if any two keys are equal according to the comparator
   */

  /**
   * Test-helper method that performs {@code nThreads} concurrent calls to {@code cache.get(key)} or
   * {@code cache.getUnchecked(key)}, and returns a List containing each of the results. The result
   * for any given call to {@code cache.get} or {@code cache.getUnchecked} is the value returned, or
   * the exception thrown.
   *
   * <p>As we iterate from {@code 0} to {@code nThreads}, threads with an even index will call

                return INT_TO_STRING_MAP.values().iterator();
              }
            },
            Functions.forMap(INT_TO_STRING_MAP.inverse()));
    assertEquals(INT_TO_STRING_MAP, outputMap);
  }

  public void testUniqueIndexIterator() {
    ImmutableMap<Integer, String> outputMap =
        Maps.uniqueIndex(

                return INT_TO_STRING_MAP.values().iterator();
              }
            },
            Functions.forMap(INT_TO_STRING_MAP.inverse()));
    assertEquals(INT_TO_STRING_MAP, outputMap);
  }

  public void testUniqueIndexIterator() {
    ImmutableMap<Integer, String> outputMap =
        Maps.uniqueIndex(