}

  public void testFutureGetThrowsWrappedError() throws Exception {
    Error error = new Error();
    inputFuture.setException(error);
    // Verify that get throws an ExecutionException, caused by an Error, when
    // the callback is called.
    listener.assertException(error);
  }

  public void testAddListenerAfterCallback() throws Throwable {
    inputFuture.set(VALID_INPUT_DATA);

     * Verifies that close can be called successfully.
     */
    @Test
    void testClose() {
        doNothing().when(smbTree).close();

        smbTree.close();

        verify(smbTree).close();
    }

    /**
     * Test for close() method called multiple times.
     * Verifies that close can be called multiple times safely.
     */
    @Test

                calledFirst.set(true);
                assertFalse(called.get());
                QueryBuilder builder = chain.execute(context, query, boost);
                assertTrue(called.get());
                return builder;
            }
        });
        queryBuilder = queryProcessor.execute(context, query, 1.0f);
        assertTrue(called.get());
        assertTrue(calledFirst.get());

You can declare that a variable can be any of **several types**, for example, an `int` or a `str`.

To define it you use the <dfn title='also called "bitwise or operator", but that meaning is not relevant here'>vertical bar (`|`)</dfn> to separate both types.

This is called a "union", because the variable can be anything in the union of those two sets of types.

```Python hl_lines="1"

        InetAddress addr = mock(InetAddress.class);
        when(addr.getHostName()).thenReturn(hostname);
        UniAddress ua = new UniAddress(addr);
        // Act
        String called = ua.firstCalledName();
        // Assert
        assertEquals(expectedPrefix, called, "firstCalledName should return uppercase prefix or SMBSERVER_NAME");
    }

    @Test
    void nextCalledNameWithNbtAddressReturnsDelegateValue() {
        // Arrange

            }
        };
        ComponentUtil.register(factory, "webApiManagerFactory");

        // Execute
        webApiFilter.doFilter(request, response, chain);

        // Verify manager was called and chain was not called directly
        assertTrue(managerCalled.get());
        assertFalse(chainCalled.get());
    }

    // Test doFilter with ServletRequest and ServletResponse (not HTTP variants)
    @Test

     *
     * @return a global context, initialized on first call
     */
    public static synchronized final SingletonContext getInstance() {
        if (INSTANCE == null) {
            try {
                log.debug("Initializing singleton context");
                init(null);
            } catch (final CIFSException e) {
                log.error("Failed to create singleton JCIFS context", e);
            }
        }

     */
    public void healthy() {}

    /**
     * Called when the all of the component services have reached a terminal state, either
     * {@linkplain State#TERMINATED terminated} or {@linkplain State#FAILED failed}.
     */
    public void stopped() {}

    /**
     * Called when a component service has {@linkplain State#FAILED failed}.
     *

 *
 * <p>The service is called during model building for all model objects, allowing
 * implementations to decide which objects to process and how to optimize them.</p>
 *
 * @since 4.0.0
 */
public interface ModelObjectProcessor {

    /**
     * Process a model object, potentially returning a pooled or optimized version.
     *
     * <p>This method is called during model building for various model objects.

### Other utility functions { #other-utility-functions }

Any other utility function that you call directly can be created with normal `def` or `async def` and FastAPI won't affect the way you call it.

This is in contrast to the functions that FastAPI calls for you: *path operation functions* and dependencies.