* entire stream. To avoid a potentially expensive operation, see {@link #lengthIfKnown}.
   *
   * <p>The default implementation calls {@link #lengthIfKnown} and returns the value if present. If
   * absent, it will fall back to a heavyweight operation that will open a stream, {@link
   * Reader#skip(long) skip} to the end of the stream, and return the total number of chars that

        // of executing. Don't null out the latestTaskQueue field, because the work done here
        // may have scheduled more operations on another thread, and if those operations then
        // trigger reentrant calls that thread will have updated the latestTaskQueue field, and
        // we'd be interfering with their operation.
        executingTaskQueue.thread = null;
      }
    }

    private boolean trySetStarted() {

      return super.writeReplace();
    }
  }

  /**
   * Guaranteed to throw an exception and leave the list unmodified.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Unsupported operation.
   */
  @CanIgnoreReturnValue
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public final boolean addAll(int index, Collection<? extends E> newElements) {

	EndTime   time.Time   `msg:"stopTs"`  // Time at which rebalance operation completed or rebalance-stop was called
	Status    rebalStatus `msg:"status"`  // Current state of rebalance operation. One of Started|Stopped|Completed|Failed.
}

// rebalanceMeta contains information pertaining to an ongoing rebalance operation.
type rebalanceMeta struct {

    return fromLongBits(value);
  }

  /**
   * Returns a {@code UnsignedLong} representing the same value as the specified {@code BigInteger}.
   * This is the inverse operation of {@link #bigIntegerValue()}.
   *
   * @throws IllegalArgumentException if {@code value} is negative or {@code value >= 2^64}
   */
  @CanIgnoreReturnValue
  public static UnsignedLong valueOf(BigInteger value) {

    return fromLongBits(value);
  }

  /**
   * Returns a {@code UnsignedLong} representing the same value as the specified {@code BigInteger}.
   * This is the inverse operation of {@link #bigIntegerValue()}.
   *
   * @throws IllegalArgumentException if {@code value} is negative or {@code value >= 2^64}
   */
  @CanIgnoreReturnValue
  public static UnsignedLong valueOf(BigInteger value) {

<img src="/img/tutorial/body/image02.png">

## Editor support

In your editor, inside your function you will get type hints and completion everywhere (this wouldn't happen if you received a `dict` instead of a Pydantic model):

<img src="/img/tutorial/body/image03.png">

You also get error checks for incorrect type operations:

	timer := time.NewTimer(testDrwMutexRefreshInterval * 2)

	select {
	case <-ctx.Done():
		t.Fatal("Lock context canceled which is not expected")
	case <-timer.C:
	}

	// Should be safe operation in all cases
	dm.Unlock(context.Background())
}

// Test canceling context while quorum servers report lock not found
func TestFailedRefreshLock(t *testing.T) {
	if testing.Short() {

        ERROR_MORE_DATA, ERROR_SERVICE_NOT_INSTALLED, ERROR_NO_BROWSER_SERVERS_FOUND,
    };

    static final String[] WINERR_MESSAGES = {
        "The operation completed successfully.", "Access is denied.",
        "No more connections can be made to this remote computer at this time because there are already as many connections as the computer can accept.",

# Response Headers

## Use a `Response` parameter

You can declare a parameter of type `Response` in your *path operation function* (as you can do for cookies).

And then you can set headers in that *temporal* response object.

```Python hl_lines="1  7-8"
{!../../docs_src/response_headers/tutorial002.py!}
```

And then you can return any object you need, as you normally would (a `dict`, a database model, etc).