* 0}.
   *
   * @throws IllegalArgumentException if {@code a < 0} or {@code b < 0}
   */
  public static int gcd(int a, int b) {
    /*
     * The reason we require both arguments to be >= 0 is because otherwise, what do you return on
     * gcd(0, Integer.MIN_VALUE)? BigInteger.gcd would return positive 2^31, but positive 2^31 isn't
     * an int.
     */
    checkNonNegative("a", a);

      // extra zero bits we need to add to the end of bitsPerChar to get 3 in total.
      // The logic here would be wrong for bitsPerChar > 8, but since we require distinct ASCII
      // characters that can't happen.
      int zeroesInBitsPerChar = Integer.numberOfTrailingZeros(bitsPerChar);
      this.charsPerChunk = 1 << (3 - zeroesInBitsPerChar);

  }

  /**
   * Returns true if the given member is a method that overrides {@link Object#equals(Object)}.
   *
   * <p>The documentation for {@link Object#equals} says it should accept null, so don't require an
   * explicit {@code @Nullable} annotation (see <a
   * href="https://github.com/google/guava/issues/1819">#1819</a>).
   *

    @Retention(RetentionPolicy.RUNTIME)
    @Inherited
    @TesterAnnotation
    @interface Require {
      ExampleDerivedFeature[] value() default {};

      ExampleDerivedFeature[] absent() default {};
    }
  }

  @Retention(RetentionPolicy.RUNTIME)
  @interface NonTesterAnnotation {}

  @ExampleBaseFeature.Require({ExampleBaseFeature.BASE_FEATURE_1})

 *       {@link #poll} and {@link #remove()}) run in {@code O(log n) time}.
 *   <li>The {@link #remove(Object)} and {@link #contains} operations require linear ({@code O(n)})
 *       time.
 *   <li>If you only access one end of the queue, and don't use a maximum size, this class is
 *       functionally equivalent to {@link PriorityQueue}, but significantly slower.
 * </ul>

   *       (In simple cases, callers can avoid this by registering all tasks with the same {@link
   *       MoreExecutors#newSequentialExecutor} wrapper around {@code directExecutor()}. More
   *       complex cases may require using thread pools or making deeper changes.)
   *   <li>If an exception propagates out of a {@code Runnable}, it is not necessarily seen by any

 * void submitPacket(byte[] packet) {
 *   rateLimiter.acquire(packet.length);
 *   networkService.send(packet);
 * }
 * }</pre>
 *
 * <p>It is important to note that the number of permits requested <i>never</i> affects the
 * throttling of the request itself (an invocation to {@code acquire(1)} and an invocation to {@code
 * acquire(1000)} will result in exactly the same throttling, if any), but it affects the throttling

    limiter.acquire(Integer.MAX_VALUE / 4);
    limiter.acquire(Integer.MAX_VALUE / 2);
    limiter.acquire(Integer.MAX_VALUE);
    assertEvents("R0.00", "R0.00", "R0.00"); // no wait, infinite rate!

    limiter.setRate(2.0);
    limiter.acquire();
    limiter.acquire();
    limiter.acquire();
    limiter.acquire();
    limiter.acquire();
    assertEvents(

   *   Long.MIN_VALUE or Long.MAX_VALUE.
   * - Favor responding to interrupts over timeouts.
   * - System.nanoTime() is expensive enough that we want to call it the minimum required number of
   *   times, typically once before invoking a blocking method. This often requires keeping track of
   *   the first time in a method that nanoTime() has been invoked, for which the special value 0L

 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express