<img class="shadow" src="/img/deployment/concepts/image01.png">

---

Now that we know the difference between the terms **process** and **program**, let's continue talking about deployments.

## Running on Startup { #running-on-startup }

    // JVM shutdown will not be prevented from exiting after this service has stopped or failed.
    // Technically this listener is added after start() was called so it is a little gross, but it
    // is called within doStart() so we know that the service cannot terminate or fail concurrently
    // with adding this listener so it is impossible to miss an event that we are interested in.
    addListener(
        new Listener() {
          @Override

    protected Long maxContentLength = null;

    /**
     * Constructs a new AbstractCrawlerClient.
     */
    public AbstractCrawlerClient() {
        // NOP
    }

    /**
     * Initializes the client with parameters from initParamMap.
     * Sets maxContentLength, accessTimeout, and maxCachedContentSize.
     */
    public void init() {
        // max content length

      return false
    }
    // An example of one we might want to retry with a different route is a problem connecting to a
    // proxy and would manifest as a standard IOException. Unless it is one we know we should not
    // retry, we return true and try a new route.
    return true
  }

  /**
   * Figures out the HTTP request to make in response to receiving [userResponse]. This will

                modelRequest.setTwoPhaseBuilding(false);
                // This merge is on purpose because otherwise user properties would override model
                // properties in dependencies the user does not know. See MNG-7563 for details.
                modelRequest.setSystemProperties(
                        toProperties(session.getUserProperties(), session.getSystemProperties()));

These examples are intentionally simple, but show how it all works.

In the chapters about security, there are utility functions that are implemented in this same way.

If you understood all this, you already know how those utility tools for security work underneath.

///

## Dependencies with `yield`, `HTTPException`, `except` and Background Tasks { #dependencies-with-yield-httpexception-except-and-background-tasks }

/// warning

* An optional `client_secret` (we don't need it for our example).

/// info

The `OAuth2PasswordRequestForm` is not a special class for **FastAPI** as is `OAuth2PasswordBearer`.

`OAuth2PasswordBearer` makes **FastAPI** know that it is a security scheme. So it is added that way to OpenAPI.

But `OAuth2PasswordRequestForm` is just a class dependency that you could have written yourself, or you could have declared `Form` parameters directly.

your report:

  - A descriptive title
  - Your name and affiliation (if any).
  - A description of the technical details of the vulnerabilities.
  - A minimal example of the vulnerability. It is very important to let us know
    how we can reproduce your findings. For memory corruption triggerable in
    TensorFlow models, please demonstrate an exploit against one of Alphabet's
    models in <https://tfhub.dev/>

    /** List of request headers */
    private final List<Header> requestHeaderList = new ArrayList<>();

    /**
     * Constructs a new ApiExtractor.
     */
    public ApiExtractor() {
        // NOP
    }

    /**
     * Initializes the API extractor, setting up the HTTP client and configuration.
     * This method is called after construction to initialize the HTTP client with

 */
public class AccessResultImpl<IDTYPE> implements AccessResult<IDTYPE> {

    /**
     * Creates a new instance of AccessResultImpl.
     */
    public AccessResultImpl() {
        // NOP
    }

    /** The unique identifier for the access result. */
    protected IDTYPE id;

    /** The session ID associated with the access result. */
    protected String sessionId;