}
    return x;
  }

  static void checkRoundingUnnecessary(boolean condition) {
    if (!condition) {
      throw new ArithmeticException("mode was UNNECESSARY, but rounding was necessary");
    }
  }

  static void checkInRangeForRoundingInputs(boolean condition, double input, RoundingMode mode) {
    if (!condition) {
      throw new ArithmeticException(

   * values are even integers; this method returns the one that is a multiple of a greater power of
   * two.)
   *
   * @throws ArithmeticException if {@code mode} is {@link RoundingMode#UNNECESSARY} and {@code x}
   *     is not precisely representable as a {@code double}
   * @since 30.0
   */
  public static double roundToDouble(BigDecimal x, RoundingMode mode) {

 * not its subclasses) can be reused when copied from one ImmutableMap to another.
 *
 * @author Louis Wasserman
 */
@GwtIncompatible // unnecessary
class ImmutableMapEntry<K, V> extends SimpleImmutableEntry<K, V> {
  /**
   * Creates an {@code ImmutableMapEntry} array to hold parameterized entries. The result must never

   * values are even integers; this method returns the one that is a multiple of a greater power of
   * two.)
   *
   * @throws ArithmeticException if {@code mode} is {@link RoundingMode#UNNECESSARY} and {@code x}
   *     is not precisely representable as a {@code double}
   * @since 30.0
   */
  public static double roundToDouble(BigDecimal x, RoundingMode mode) {

   * each appears first in the source collection.
   *
   * <p><b>Performance note:</b> This method will sometimes recognize that the actual copy operation
   * is unnecessary; for example, {@code copyOf(copyOf(anArrayList))} will copy the data only once.
   * This reduces the expense of habitually making defensive copies at API boundaries. However, the

    // than wrapping cbuf in a light-weight CharSequence.
    target.append(new String(cbuf, off, len));
  }

  /*
   * Override a few functions for performance reasons to avoid creating unnecessary strings.
   */

  @Override
  public void write(int c) throws IOException {
    checkNotClosed();
    target.append((char) c);
  }

  @Override
  public void write(String str) throws IOException {

import static java.lang.Double.NaN;
import static java.lang.Double.POSITIVE_INFINITY;
import static java.math.RoundingMode.CEILING;
import static java.math.RoundingMode.FLOOR;
import static java.math.RoundingMode.UNNECESSARY;
import static org.junit.Assert.assertThrows;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Ordering;

import static java.lang.Double.NaN;
import static java.lang.Double.POSITIVE_INFINITY;
import static java.math.RoundingMode.CEILING;
import static java.math.RoundingMode.FLOOR;
import static java.math.RoundingMode.UNNECESSARY;
import static org.junit.Assert.assertThrows;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Ordering;

  //    assigned prior to calling addListener, and addListener happens-before any invocation of the
  //    listener. Notably, this means that 'volatile' is unnecessary to make 'inputFuture' visible
  //    to the listener.
  //
  // 2. In done() where we may propagate cancellation to the input. In this case it is _not_ fine.

  /**
   * Figures out the HTTP request to make in response to receiving [userResponse]. This will
   * either add authentication headers, follow redirects or handle a client request timeout. If a
   * follow-up is either unnecessary or not applicable, this returns null.
   */
  @Throws(IOException::class)
  private fun followUpRequest(
    userResponse: Response,
    exchange: Exchange?,
  ): Request? {