assertFailsToDecode(base64(), "Wf2!", "Unrecognized character: !");
    // This sentence just isn't base64() encoded.
    assertFailsToDecode(base64(), "let's not talk of love or chains!");
    // A 4n+1 length string is never legal base64().
    assertFailsToDecode(base64(), "12345", "Invalid input length 5");

  @GwtIncompatible // used only from suite
  private static ImmutableDoubleArray makeArray(Double[] values) {
    return ImmutableDoubleArray.copyOf(Arrays.asList(values));
  }

  // Test generators.  To let the GWT test suite generator access them, they need to be public named
  // classes with a public default constructor (not that we run these suites under GWT yet).

  @J2ktIncompatible
  @GwtIncompatible // used only from suite

  @J2ktIncompatible
  @GwtIncompatible // used only from suite
  private static ImmutableLongArray makeArray(Long[] values) {
    return ImmutableLongArray.copyOf(Arrays.asList(values));
  }

  // Test generators.  To let the GWT test suite generator access them, they need to be public named
  // classes with a public default constructor (not that we run these suites under GWT yet).

  @J2ktIncompatible
  @GwtIncompatible // used only from suite

        if (array[min] > array[index]) {
          min = index;
        }
      }
      if (min != from) {
        swap(array, min, from);
      }
      return;
    }

    // Let's play quickselect! We'll repeatedly partition the range [from, to] containing the
    // required element, as long as it has more than one element.
    while (to > from) {
      int partitionPoint = partition(array, from, to);

   */
  @GwtIncompatible // TODO
  public static long sqrt(long x, RoundingMode mode) {
    checkNonNegative("x", x);
    if (fitsInInt(x)) {
      return IntMath.sqrt((int) x, mode);
    }
    /*
     * Let k be the true value of floor(sqrt(x)), so that
     *
     *            k * k <= x          <  (k + 1) * (k + 1)
     * (double) (k * k) <= (double) x <= (double) ((k + 1) * (k + 1))

      setException(t);
      return;
    } finally {
      function = null;
    }

    /*
     * If set()/setValue() throws an Error, we let it propagate. Why? The most likely Error is a
     * StackOverflowError (from deep transform(..., directExecutor()) nesting), and calling
     * setException(stackOverflowError) would fail:
     *

    assertFailsToDecode(base64(), "Wf2!", "Unrecognized character: !");
    // This sentence just isn't base64() encoded.
    assertFailsToDecode(base64(), "let's not talk of love or chains!");
    // A 4n+1 length string is never legal base64().
    assertFailsToDecode(base64(), "12345", "Invalid input length 5");

      this.original = original;
    }

    /*
     * These gymnastics are a little confusing. Basically this class has neither legacy nor
     * non-legacy behavior; it just needs to let the behavior of the backing converter shine
     * through. So, we override the correctedDo* methods, after which the do* methods should never
     * be reached.
     */

    @Override
    protected A doForward(B b) {

      if (iterations >= maxIterations) {
        @SuppressWarnings("nullness") // safe because we pass sort() a range that contains real Ts
        T[] castBuffer = (T[]) buffer;
        // We've already taken O(k log k), let's make sure we don't take longer than O(k log k).
        Arrays.sort(castBuffer, left, right + 1, comparator);
        break;
      }
    }
    bufferSize = k;

   *        0 +----------+-------+--------------→ storedPermits
   *          0 thresholdPermits maxPermits
   * </pre>
   *
   * Before going into the details of this particular function, let's keep in mind the basics:
   *
   * <ol>
   *   <li>The state of the RateLimiter (storedPermits) is a vertical line in this figure.
   *   <li>When the RateLimiter is not used, this goes right (up to maxPermits)