/** A bit mask which selects the bit encoding ASCII character case. */
  private static final char CASE_MASK = 0x20;

  /**
   * Returns a copy of the input string in which all {@linkplain #isUpperCase(char) uppercase ASCII
   * characters} have been converted to lowercase. All other characters are copied without
   * modification.
   */
  public static String toLowerCase(String string) {
    int length = string.length();

   * types (or if the type is a non-variable type, like {@code String}), then code should almost
   * never use this method, preferring instead to call {@code requireNonNull} so as to benefit from
   * its runtime check.
   *
   * <p>An example use case for this method is in implementing an {@code Iterator<T>} whose {@code

    checkNotNull(callable);
    checkNotNull(listeningExecutorService);
    return () -> listeningExecutorService.submit(callable);
  }

  /**
   * Wraps the given callable such that for the duration of {@link Callable#call} the thread that is
   * running will have the given name.
   *
   * @param callable The callable to wrap
   * @param nameSupplier The supplier of thread names, {@link Supplier#get get} will be called once

   * types (or if the type is a non-variable type, like {@code String}), then code should almost
   * never use this method, preferring instead to call {@code requireNonNull} so as to benefit from
   * its runtime check.
   *
   * <p>An example use case for this method is in implementing an {@code Iterator<T>} whose {@code

     * null} if {@code remove()} or {@code add()} has been called more recently than either. We use
     * this to determine which stack to pop from on a call to {@code remove()} (or to pop from and
     * push to on a call to {@code set()}).
     */
    @Nullable Stack<E> stackWithLastReturnedElementAtTop = null;

    MultiExceptionListIterator(List<E> expectedElements) {

    // We'd like for all the following to compile.
    ListenableFuture<String> unused;

    // Compiles:
    unused = whenAllComplete(futureA, futureB).call(combiner, directExecutor());

    // Does not compile:
    // unused = whenAllComplete(futures).call(combiner);

    // Workaround for the above:
    unused = whenAllComplete(asList(futures)).call(combiner, directExecutor());
  }

    // We'd like for all the following to compile.
    ListenableFuture<String> unused;

    // Compiles:
    unused = whenAllComplete(futureA, futureB).call(combiner, directExecutor());

    // Does not compile:
    // unused = whenAllComplete(futures).call(combiner);

    // Workaround for the above:
    unused = whenAllComplete(asList(futures)).call(combiner, directExecutor());
  }

        guard.setSatisfied(true);
        break;
      case SATISFIED_WHILE_WAITING:
        guard.setSatisfied(false);
        enterSatisfyGuardAndLeaveInAnotherThread(); // enter blocks until we call waitFor
        break;
      case UNSATISFIED_BEFORE_AND_WHILE_WAITING:
        guard.setSatisfied(false);
        break;
      case SATISFIED_AND_INTERRUPTED_BEFORE_WAITING:
        guard.setSatisfied(true);

  }

  public void testPadStart_negativeMinLength() {
    assertThat(Strings.padStart("x", -1, '-')).isSameInstanceAs("x");
  }

  @SuppressWarnings("nullness") // test of a bogus call
  public void testPadStart_null() {
    assertThrows(NullPointerException.class, () -> Strings.padStart(null, 5, '0'));
  }

  public void testPadEnd_noPadding() {

    String expected = "TestClass{field1=1, value1, field2=value2}";

    assertThat(helper.toString()).isEqualTo(expected);
    // Call toString again
    assertThat(helper.toString()).isEqualTo(expected);

    // Make sure the cached value is reset when we modify the helper at all
    String expected2 = "TestClass{field1=1, value1, field2=value2, 2}";
    helper.addValue(2);