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

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

{* ../../docs_src/events/tutorial003.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*.

		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrAccessDenied), r.URL)
		return
	}

	kmsContext := kms.Context{"MinIO admin API": "KMSKeyStatusHandler"} // Context for a test key operation
	// 1. Generate a new key using the KMS.
	key, err := GlobalKMS.GenerateKey(ctx, &kms.GenerateKeyRequest{Name: keyID, AssociatedData: kmsContext})
	if err != nil {
		response.EncryptionErr = err.Error()

   *
   * <p>Currently, this method is invoked while holding a lock. If an implementation of this method
   * blocks, it can prevent this service from changing state. If you need to performing a blocking
   * operation in order to trigger shutdown, consider instead registering a listener and
   * implementing {@code stopping}. Note, however, that {@code stopping} does not run at exactly the
   * same times as {@code triggerShutdown}.
   */

 * "The .NET Developer's Guide to Windows Security" (which is also
 * available online).
 * <p>
 * Direct ACEs are evaluated first in order. The SID of the user performing
 * the operation and the desired access bits are compared to the SID
 * and access mask of each ACE. If the SID matches, the allow/deny flags
 * and access mask are considered. If the ACE is a "deny"

///

/// warning | "注意"

*path operation*で複数の`Form`パラメータを宣言することができますが、JSONとして受け取ることを期待している`Body`フィールドを宣言することはできません。なぜなら、リクエストは`application/json`の代わりに`application/x-www-form-urlencoded`を使ってボディをエンコードするからです。

これは **FastAPI**の制限ではなく、HTTPプロトコルの一部です。

///

## まとめ

  // a creation or deletion of related object.
  // +optional
  optional k8s.io.api.core.v1.ObjectReference related = 9;

  // note is a human-readable description of the status of this operation.
  // Maximal length of the note is 1kB, but libraries should be prepared to
  // handle values up to 64kB.
  // +optional
  optional string note = 10;

   */
  @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait.
  public void testDirectoryDeletion_directorySymlinkRace() throws IOException {
    int iterations = isAndroid() ? 100 : 5000;
    for (DirectoryDeleteMethod method : EnumSet.allOf(DirectoryDeleteMethod.class)) {
      try (FileSystem fs = newTestFileSystem(SECURE_DIRECTORY_STREAM)) {

	// Log unhandled errors.
	if _, ok := err.(BucketPolicyNotFound); !ok {
		internalLogIf(GlobalContext, err, logger.WarningKind)
	}

	// As policy is not available for given bucket name, returns IsOwner i.e.
	// operation is allowed only for owner.
	return args.IsOwner
}

// NewPolicySys - creates new policy system.
func NewPolicySys() *PolicySys {
	return &PolicySys{}
}

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

  ...
}
```

### Events with Failures

		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
}