# Dependencies with yield

FastAPI supports dependencies that do some <abbr title='sometimes also called "exit code", "cleanup code", "teardown code", "closing code", "context manager exit code", etc.'>extra steps after finishing</abbr>.

To do this, use `yield` instead of `return`, and write the extra steps (code) after.

/// tip

Make sure to use `yield` one single time per dependency.

///

/// note | "Technical Details"

   *
   * @throws IllegalArgumentException if the resource is not found
   */
  @CanIgnoreReturnValue // being used to check if a resource exists
  // TODO(cgdecker): maybe add a better way to check if a resource exists
  // e.g. Optional<URL> tryGetResource or boolean resourceExists
  public static URL getResource(String resourceName) {
    ClassLoader loader =
        MoreObjects.firstNonNull(

			lifecycleResponse:  []byte(""),
			errorResponse: APIErrorResponse{
				Resource: SlashSeparator + bucketName + SlashSeparator,
				Code:     "InvalidAccessKeyId",
				Message:  "The Access Key Id you provided does not exist in our records.",
			},
			shouldPass: false,
		},
		// PUT empty credentials
		{
			method:             http.MethodPut,
			bucketName:         bucketName,
			accessKey:          "",
			secretKey:          "",

                        getLogger().debug(metadata + " could not be found on repository: " + repository.getId());

                        // delete the local copy so the old details aren't used.
                        if (file.exists()) {
                            if (!file.delete()) {
                                // sleep for 10ms just in case this is windows holding a file lock
                                try {

 */
@Deprecated(since = "4.0.0")
public interface ModelLocator {

    /**
     * Locates the POM file within the specified project directory. In case the given project directory does not exist
     * or does not contain a POM file, the return value indicates the expected path to the POM file. Subdirectories of
     * the project directory will not be considered when locating the POM file. The return value will be an absolute

	if s3Error := checkRequestAuthType(ctx, r, policy.PutBucketPolicyAction, bucket, ""); s3Error != ErrNone {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(s3Error), r.URL)
		return
	}

	// Check if bucket exists.
	if _, err := objAPI.GetBucketInfo(ctx, bucket, BucketOptions{}); err != nil {
		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
		return
	}

	// Error out if Content-Length is missing.

            if (!result.isEmpty()) {
                delete(userDN, adminEnv);
            } else {
                logger.info("{} does not exist in LDAP server.", user.getName());
            }
        });

    }

    public void insert(final Role role) {
        if (!fessConfig.isLdapAdminEnabled()) {
            return;
        }

	for _, target := range targets {
		if _, ok := list.targets[target.ID()]; ok {
			return fmt.Errorf("target %v already exists", target.ID())
		}
		list.targets[target.ID()] = target
	}

	return nil
}

// Exists - checks whether target by target ID exists or not.
func (list *TargetList) Exists(id TargetID) bool {
	list.RLock()
	defer list.RUnlock()

	_, found := list.targets[id]
	return found
}

	legacyFS := !(s.fsType == xfs || s.fsType == ext4)

	s.RLock()
	legacy := s.formatLegacy
	s.RUnlock()

	// Verify if volume is valid and it exists.
	volumeDir, err := s.getVolDir(opts.Bucket)
	if err != nil {
		return err
	}

	if !skipAccessChecks(opts.Bucket) {
		// Stat a volume entry.
		if err = Access(volumeDir); err != nil {

                              and DoesNotExist.
                            type: string
                          values:
                            description: values is an array of string values. If the
                              operator is In or NotIn, the values array must be non-empty.
                              If the operator is Exists or DoesNotExist, the values