return new Stopwatch(ticker).start();
  }

  Stopwatch() {
    this.ticker = Ticker.systemTicker();
  }

  Stopwatch(Ticker ticker) {
    this.ticker = checkNotNull(ticker, "ticker");
  }

  /**
   * Returns {@code true} if {@link #start()} has been called on this stopwatch, and {@link #stop()}
   * has not been called since the last call to {@code start()}.
   */
  public boolean isRunning() {

   */

  private final transient int start; // it happens that we only serialize instances where this is 0
  private final int end; // exclusive

  private ImmutableIntArray(int[] array) {
    this(array, 0, array.length);
  }

  private ImmutableIntArray(int[] array, int start, int end) {
    this.array = array;
    this.start = start;
    this.end = end;
  }

   */

  private final transient int start; // it happens that we only serialize instances where this is 0
  private final int end; // exclusive

  private ImmutableLongArray(long[] array) {
    this(array, 0, array.length);
  }

  private ImmutableLongArray(long[] array, int start, int end) {
    this.array = array;
    this.start = start;
    this.end = end;
  }

   */

  private final transient int start; // it happens that we only serialize instances where this is 0
  private final int end; // exclusive

  private ImmutableIntArray(int[] array) {
    this(array, 0, array.length);
  }

  private ImmutableIntArray(int[] array, int start, int end) {
    this.array = array;
    this.start = start;
    this.end = end;
  }

   */

  private final transient int start; // it happens that we only serialize instances where this is 0
  private final int end; // exclusive

  private ImmutableDoubleArray(double[] array) {
    this(array, 0, array.length);
  }

  private ImmutableDoubleArray(double[] array, int start, int end) {
    this.array = array;
    this.start = start;
    this.end = end;
  }

                    hour = 0;
            }

            if (isLeft) {
                var start = this.startDate.clone();
                start.hour(hour);
                start.minute(minute);
                start.second(second);
                this.setStartDate(start);
                if (this.singleDatePicker) {
                    this.endDate = this.startDate.clone();

    final double[] array;
    final int start;
    final int end;

    DoubleArrayAsList(double[] array) {
      this(array, 0, array.length);
    }

    DoubleArrayAsList(double[] array, int start, int end) {
      this.array = array;
      this.start = start;
      this.end = end;
    }

    @Override
    public int size() {
      return end - start;
    }

    @Override

    final int[] array;
    final int start;
    final int end;

    IntArrayAsList(int[] array) {
      this(array, 0, array.length);
    }

    IntArrayAsList(int[] array, int start, int end) {
      this.array = array;
      this.start = start;
      this.end = end;
    }

    @Override
    public int size() {
      return end - start;
    }

    @Override

    final long[] array;
    final int start;
    final int end;

    LongArrayAsList(long[] array) {
      this(array, 0, array.length);
    }

    LongArrayAsList(long[] array, int start, int end) {
      this.array = array;
      this.start = start;
      this.end = end;
    }

    @Override
    public int size() {
      return end - start;
    }

    @Override

## Lifespan

You can define this *startup* and *shutdown* logic using the `lifespan` parameter of the `FastAPI` app, and a "context manager" (I'll show you what that is in a second).

Let's start with an example and then see it in detail.