}
      }
    }
    return mutex;
  }

  RateLimiter(SleepingStopwatch stopwatch) {
    this.stopwatch = checkNotNull(stopwatch);
  }

  /**
   * Updates the stable rate of this {@code RateLimiter}, that is, the {@code permitsPerSecond}
   * argument provided in the factory method that constructed the {@code RateLimiter}. Currently

 * views are modifiable.
 *
 * <p>This class is not threadsafe when any concurrent operations update the multimap. Concurrent
 * read operations will work correctly. To allow concurrent update operations, wrap your multimap
 * with a call to {@link Multimaps#synchronizedListMultimap}.
 *
 * <p>See the Guava User Guide article on <a href=

            }
          }
        }
        if (done) {
          break;
        }
      }
    }
  }

  /**
   * Multiple threads using same array of counters successfully update a number of times equal to
   * total count
   */
  public void testCountingInMultipleThreads() throws InterruptedException {
    final AtomicDoubleArray aa = new AtomicDoubleArray(SIZE);

   * other words, no character encoding is performed; the low byte and high byte of each {@code
   * char} are hashed directly (in that order). The input must not be updated while this method is
   * in progress.
   *
   * <p><b>Warning:</b> This method will produce different output than most other languages do when

            }
          }
        }
        if (done) {
          break;
        }
      }
    }
  }

  /**
   * Multiple threads using same array of counters successfully update a number of times equal to
   * total count
   */
  public void testCountingInMultipleThreads() throws InterruptedException {
    final AtomicDoubleArray aa = new AtomicDoubleArray(SIZE);

    if (count <= 1) {
      checkArgument(count >= 0, "invalid count: %s", count);
      return (count == 0) ? "" : string;
    }

    // IF YOU MODIFY THE CODE HERE, you must update StringsRepeatBenchmark
    final int len = string.length();
    final long longSize = (long) len * (long) count;
    final int size = (int) longSize;
    if (size != longSize) {

     * iterator's next element and pass it to the reference iterator through this method so it can
     * return the same element. This enables the assertion to pass and the reference iterator to
     * properly update its state.
     */
    void promoteToNext(E e) {
      if (nextElements.remove(e)) {
        nextElements.push(e);
      } else {
        throw new UnknownElementException(nextElements, e);
      }
    }

   * out.
   */
  long timeoutMillis() {
    return SHORT_DELAY_MS / 4;
  }

  /** Returns a new Date instance representing a time delayMillis milliseconds in the future. */
  Date delayedDate(long delayMillis) {
    return new Date(System.currentTimeMillis() + delayMillis);
  }

  /** The first exception encountered if any threadAssertXXX method fails. */

  }

  /**
   * Returns a hash table for the specified keys and values, and ensures that neither keys nor
   * values are null. This method may update {@code alternatingKeysAndValues} if there are duplicate
   * keys. If so, the return value will indicate how many entries are still valid, and will also

    RateLimiter rateLimiter = RateLimiter.create(1.0, stopwatch);
    rateLimiter.acquire(1); // no wait
    rateLimiter.acquire(1); // R1.00, to repay previous

    rateLimiter.setRate(2.0); // update the rate!

    rateLimiter.acquire(1); // R1.00, to repay previous (the previous was under the old rate!)
    rateLimiter.acquire(2); // R0.50, to repay previous (now the rate takes effect)