/**
 * A {@code BiMap} backed by an {@code EnumMap} instance for keys-to-values, and a {@code HashMap}
 * instance for values-to-keys. Null keys are not permitted, but null values are. An {@code
 * EnumHashBiMap} and its inverse are both serializable.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#bimap">{@code BiMap}</a>.
 *
 * @author Mike Bostock
 * @since 2.0
 */

    ExecutorService exec = newCachedThreadPool();

    int listenerCount = 20;
    CountDownLatch listenerLatch = new CountDownLatch(listenerCount);

    // Test that listeners added both before and after the value is available
    // get called correctly.
    for (int i = 0; i < 20; i++) {

      // Right in the middle start up a thread to close the latch.
      if (i == 10) {

  public Set<EndpointPair<N>> incidentEdges(N node) {
    GraphConnections<N, V> connections = checkedConnections(node);
    IncidentEdgeSet<N> incident =
        new IncidentEdgeSet<N>(this, node, IncidentEdgeSet.EdgeType.BOTH) {
          @Override
          public Iterator<EndpointPair<N>> iterator() {
            return connections.incidentEdgeIterator(node);
          }
        };
    return nodeInvalidatableSet(incident, node);

		return errXMLNotWellFormed
	}
	return nil
}

// IsDateNull returns true if date field is null
func (t Transition) IsDateNull() bool {
	return t.Date.IsZero()
}

// IsNull returns true if both date and days fields are null
func (t Transition) IsNull() bool {
	return t.StorageClass == ""
}

// NextDue returns upcoming transition date for obj and true if applicable,
// returns false otherwise.

   * returned from {@link #asMapOfRanges} will be different if there were existing entries which
   * connect to the given range and value.
   *
   * <p>Even if the input range is empty, if it is connected on both sides by ranges mapped to the
   * same value those two ranges will be coalesced.
   *
   * <p><b>Note:</b> coalescing requires calling {@code .equals()} on any connected values, which

 */
public final class ModelVersionUtils {

    private ModelVersionUtils() {
        // Utility class
    }

    /**
     * Detects the model version from a POM document.
     * Uses both the modelVersion element and namespace URI for detection.
     *
     * @param pomDocument the POM document (domtrip Document)
     * @return the detected model version
     */

      }
    }
  }
  return result.toTypedArray()
}

/**
 * Returns true if there is an element in this array that is also in [other]. This method terminates
 * if any intersection is found. The sizes of both arguments are assumed to be so small, and the
 * likelihood of an intersection so great, that it is not worth the CPU cost of sorting or the
 * memory cost of hashing.
 */
internal fun Array<String>.hasIntersection(

		// If empty host means it is localhost
		addr2Local = true
	} else if addr2Local, err = isLocalHost(host2, port2, port2); err != nil {
		// Host not empty, check if it is local
		return false, err
	}

	// If both of addresses point to the same machine, check if
	// have the same port
	if addr1Local && addr2Local {
		if port1 == port2 {
			return true, nil
		}
	}
	return false, nil
}

# Usage

## Single Payload Requests

Single payload requests are requests and responses that are sent in a single message.
In essence, they are `[]byte` -> `[]byte, error` functions.

It is not possible to return *both* an error and a response.

Handlers are registered on the manager using `(*Manager).RegisterSingleHandler(id HandlerID, h SingleHandlerFn, subroute ...string)`.

{!> ../../docs_src/python_types/tutorial008b_py310.py!}
```

////

//// tab | Python 3.9+

```Python hl_lines="1  4"
{!> ../../docs_src/python_types/tutorial008b_py39.py!}
```

////

In both cases this means that `item` could be an `int` or a `str`.

#### Possibly `None` { #possibly-none }

You can declare that a value could have a type, like `str`, but that it could also be `None`.