*/
  public boolean isRunning() {
    return isRunning;
  }

  /**
   * Starts the stopwatch.
   *
   * @return this {@code Stopwatch} instance
   * @throws IllegalStateException if the stopwatch is already running.
   */
  @CanIgnoreReturnValue
  public Stopwatch start() {
    checkState(!isRunning, "This stopwatch is already running.");
    isRunning = true;
    startTick = ticker.read();

    return getClass().getSimpleName();
  }

  @Override
  public String toString() {
    return serviceName() + " [" + state() + "]";
  }

  @Override
  public final boolean isRunning() {
    return delegate.isRunning();
  }

  @Override
  public final State state() {
    return delegate.state();
  }

  /** @since 13.0 */
  @Override