fail("Expected CIFSException");
        } catch (CIFSException e) {
            // Expected
        }

        assertFalse(context.isValid());

        // Further operations on invalid context should fail
        assertThrows(CIFSException.class, () -> {
            preauthService.updatePreauthHash(sessionId, "test".getBytes());
        });
    }

    @Test

        assertFalse(mockService.processHeartbeat(regId, 4));
    }

    /**
     * Test error conditions and edge cases
     */
    @Test
    void testErrorConditions() {
        // Test operations on empty service
        assertEquals(0, mockService.getRegistrationCount());
        assertFalse(mockService.hasRegistration("non-existent"));
        assertFalse(mockService.unregisterWitness("non-existent"));

 *       instance each time they are called. The caller is responsible for ensuring that the
 *       returned writer is closed.
 *   <li><b>Convenience methods:</b> These are implementations of common operations that are
 *       typically implemented by opening a writer using one of the methods in the first category,
 *       doing something and finally closing the writer that was opened.
 * </ul>
 *

import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.NavigableSet;
import java.util.TreeSet;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests operations on a NavigableSet. Can't be invoked directly; please
 * see {@code NavigableSetTestSuiteBuilder}.
 *
 * @author Jesse Wilson
 * @author Louis Wasserman
 */
@GwtIncompatible

        return new MetricsEventListener(call);
      } else {
        return EventListener.NONE;
      }
    }
  };

  ...
}
```

### Events with Failures

{* ../../docs_src/metadata/tutorial004_py39.py hl[21,26] *}

/// info | Informação

Leia mais sobre tags em [Configuração de operação de rota](path-operation-configuration.md#tags){.internal-link target=_blank}.

///

### Cheque os documentos { #check-the-docs }

Agora, se você verificar a documentação, ela exibirá todos os metadados adicionais:

		return
	}
	offset = (0xe << 24) | // opcode
		(op1 << 20) | // MCR/MRC
		((int64(bits) ^ arm.C_SCOND_XOR) << 28) | // scond
		((x0 & 15) << 8) | //coprocessor number
		((x1 & 7) << 21) | // coprocessor operation
		((x2 & 15) << 12) | // ARM register
		((x3 & 15) << 16) | // Crn
		((x4 & 15) << 0) | // Crm
		((x5 & 7) << 5) | // coprocessor information
		(1 << 4) /* must be set */
	return offset, arm.AMRC, true
}

   *
   * <p>If the mapped keys or values contain duplicates (according to {@link
   * Object#equals(Object)}), an {@code IllegalArgumentException} is thrown when the collection
   * operation is performed. (This differs from the {@code Collector} returned by {@link
   * Collectors#toMap(Function, Function)}, which throws an {@code IllegalStateException}.)
   *
   * @since 33.2.0 (available since 21.0 in guava-jre)

Erstellen Sie zunächst einen neuen `APIRouter`, der einen oder mehrere Callbacks enthält.

{* ../../docs_src/openapi_callbacks/tutorial001_py310.py hl[1,23] *}

### Die Callback-*Pfadoperation* erstellen { #create-the-callback-path-operation }

Um die Callback-*Pfadoperation* zu erstellen, verwenden Sie denselben `APIRouter`, den Sie oben erstellt haben.

Sie sollte wie eine normale FastAPI-*Pfadoperation* aussehen:

We create an async function `lifespan()` with `yield` like this:

{* ../../docs_src/events/tutorial003_py39.py hl[16,19] *}

Here we are simulating the expensive *startup* operation of loading the model by putting the (fake) model function in the dictionary with machine learning models before the `yield`. This code will be executed **before** the application **starts taking requests**, during the *startup*.