*
   * If there are I/O problems during iteration, this iterator fails silently. For example, if the
   * hosting filesystem becomes unreachable, the iterator will omit elements rather than throwing
   * exceptions.
   *
   * **The caller must [close][Snapshot.close]** each snapshot returned by [Iterator.next]. Failing
   * to do so leaks open files!
   */
  @Synchronized
  @Throws(IOException::class)

   * However, this method doesn't throw an exception in that situation, but instead keeps the
   * original {@code fromKey}. Similarly, this method keeps the original {@code toKey}, instead of
   * throwing an exception, if passed a {@code toKey} greater than an earlier {@code toKey}.
   */
  @Override
  public ImmutableSortedMap<K, V> subMap(K fromKey, K toKey) {
    return subMap(fromKey, true, toKey, false);
  }

   * AssertionFailedError thrown, so that the current testcase will fail.
   */
  public void threadAssertFalse(boolean b) {
    try {
      assertFalse(b);
    } catch (AssertionFailedError t) {
      threadRecordFailure(t);
      throw t;
    }
  }

  /**
   * Just like assertNull(x), but additionally recording (using threadRecordFailure) any

     * <p>If the combiningCallable throws an {@code ExecutionException}, the cause of the thrown
     * {@code ExecutionException} will be extracted and used as the failure of the derived step.
     *
     * <p>If the combiningCallable throws any other exception, it will be used as the failure of the
     * derived step.
     *
     * <p>If an exception is thrown after the combiningCallable creates a {@code ClosingFuture},

        /*
         * We can't just return the iterator because an immediate call to its
         * remove() method would remove one of the skipped elements instead of
         * throwing an IllegalStateException.
         */
        return new Iterator<T>() {
          boolean atStart = true;

          @Override
          public boolean hasNext() {
            return iterator.hasNext();

   * fromElement}. However, this method doesn't throw an exception in that situation, but instead
   * keeps the original {@code fromElement}. Similarly, this method keeps the original {@code
   * toElement}, instead of throwing an exception, if passed a {@code toElement} greater than an
   * earlier {@code toElement}.
   */
  @Override
  public ImmutableSortedSet<E> subSet(E fromElement, E toElement) {

  }

  public void testPuttingTheSameKeyTwiceThrowsOnBuild() {
    Builder<String, Integer> builder =
        new Builder<String, Integer>()
            .put("one", 1)
            .put("one", 1); // throwing on this line might be better but it's too late to change

    assertThrows(IllegalArgumentException.class, () -> builder.buildOrThrow());
  }

  public void testBuildKeepingLast_allowsOverwrite() {

   * {@code '-'} (<code>'&#92;u002D'</code>) is recognized as the minus sign.
   *
   * <p>Unlike {@link Float#parseFloat(String)}, this method returns {@code null} instead of
   * throwing an exception if parsing fails. Valid inputs are exactly those accepted by {@link
   * Float#valueOf(String)}, except that leading and trailing whitespace is not permitted.
   *

   * {@code '-'} (<code>'&#92;u002D'</code>) is recognized as the minus sign.
   *
   * <p>Unlike {@link Double#parseDouble(String)}, this method returns {@code null} instead of
   * throwing an exception if parsing fails. Valid inputs are exactly those accepted by {@link
   * Double#valueOf(String)}, except that leading and trailing whitespace is not permitted.
   *

   * {@code '-'} (<code>'&#92;u002D'</code>) is recognized as the minus sign.
   *
   * <p>Unlike {@link Float#parseFloat(String)}, this method returns {@code null} instead of
   * throwing an exception if parsing fails. Valid inputs are exactly those accepted by {@link
   * Float#valueOf(String)}, except that leading and trailing whitespace is not permitted.
   *