These examples run the server program (e.g Uvicorn), starting **a single process**, listening on all the IPs (`0.0.0.0`) on a predefined port (e.g. `80`).

This is the basic idea. But you will probably want to take care of some additional things, like:

* Security - HTTPS
* Running on startup
* Restarts
* Replication (the number of processes running)
* Memory
* Previous steps before starting

     */
    FAILED,
  }

  /**
   * A listener for the various state changes that a {@link Service} goes through in its lifecycle.
   *
   * <p>All methods are no-ops by default, implementors should override the ones they care about.
   *
   * @author Luke Sandberg
   * @since 15.0 (present as an interface in 13.0)
   */
  abstract class Listener {
    /** Constructor for use by subclasses. */

But I'll show you how to improve that next. 🤓

## Custom Operation IDs and Better Method Names { #custom-operation-ids-and-better-method-names }

You can **modify** the way these operation IDs are **generated** to make them simpler and have **simpler method names** in the clients.

              // it's unnecessary to waste cycles looking at them. This check is built on the
              // observation that the header entries we care about are in adjacent pairs, and we
              // always know the first index of the pair.
              if (STATIC_HEADER_TABLE[headerNameIndex - 1].value == value) {
                headerIndex = headerNameIndex

	if ifNoneMatchETagHeader != "" {
		if isETagEqual(objInfo.ETag, ifNoneMatchETagHeader) {
			// Do not care If-Modified-Since, Because:
			// 1. If If-Modified-Since condition evaluates to true.
			//  If both of the If-None-Match and If-Modified-Since headers are present in the request as follows:
			// 	If-None-Match condition evaluates to false , and;
			//  If-Modified-Since condition evaluates to true ;

   *       to construct the sample instances. In case of tie, the candidate constructors or
   *       factories are tried one after another until one can be used to construct sample
   *       instances.
   *   <li>For the constructor or static factory method used to construct instances, it's checked
   *       that when equal parameters are passed, the result instance should also be equal; and vice
   *       versa.

 * that they are safe for concurrent use, but if other threads modify the map after the iterator is
 * created, it is undefined which of these changes, if any, are reflected in that iterator. These
 * iterators never throw {@link ConcurrentModificationException}.
 *
 * <p>If {@link #weakKeys} or {@link #weakValues} are requested, it is possible for a key or value

     */
    FAILED,
  }

  /**
   * A listener for the various state changes that a {@link Service} goes through in its lifecycle.
   *
   * <p>All methods are no-ops by default, implementors should override the ones they care about.
   *
   * @author Luke Sandberg
   * @since 15.0 (present as an interface in 13.0)
   */
  abstract class Listener {
    /** Constructor for use by subclasses. */

So, **FastAPI** will take care of filtering out all the data that is not declared in the output model (using Pydantic).

### `response_model` or Return Type { #response-model-or-return-type }

In this case, because the two models are different, if we annotated the function return type as `UserOut`, the editor and tools would complain that we are returning an invalid type, as those are different classes.

      switch (c) {
        case '\t':
        case '\n':
        case '\013':
        case '\f':
        case '\r':
        case ' ':
        case '\u0085':
        case '\u1680':
        case '\u2028':
        case '\u2029':
        case '\u205f':
        case '\u3000':
          return true;
        case '\u2007':
          return false;
        default: