*  @author Victor Jonsson, http://victorjonsson.se
 *  @license MIT
 */

 *  @author Victor Jonsson, http://victorjonsson.se
 *  @license MIT
 */

By default, what the method `.openapi()` does is check the property `.openapi_schema` to see if it has contents and return them.

If it doesn't, it generates them using the utility function at `fastapi.openapi.utils.get_openapi`.

And that function `get_openapi()` receives as parameters:

* `title`: The OpenAPI title, shown in the docs.
* `version`: The version of your API, e.g. `2.5.0`.

 * @return {boolean} Whether the given string is null or is the empty string.
 * @public
 */
Platform.stringIsNullOrEmpty = function(str) {
  return !str;
};


/**
 * @param {?string} str
 * @return {string} Original str, if it is non-null. Otherwise empty string.
 */
Platform.nullToEmpty = function(str) {
  return str || "";
};


/**
 * @param {?string} str

 *  @author Victor Jonsson, http://victorjonsson.se
 *  @license MIT
 */

{!../../docs_src/custom_response/tutorial008.py!}
```

1. This is the generator function. It's a "generator function" because it contains `yield` statements inside.
2. By using a `with` block, we make sure that the file-like object is closed after the generator function is done. So, after it finishes sending the response.

 *  @author Victor Jonsson, http://victorjonsson.se
 *  @license MIT
 */

Op een gegeven moment zou je aan de definitie van de functie zijn begonnen, je had de parameters klaar...

Maar dan moet je “die methode die de eerste letter naar hoofdletters converteert” aanroepen.

Was het `upper`? Was het `uppercase`? `first_uppercase`? `capitalize`?

Dan roep je de hulp in van je oude programmeursvriend, (automatische) code aanvulling in je editor.

 *  @website http://formvalidator.net/
 *  @author Victor Jonsson, http://victorjonsson.se
 *  @license MIT
 */

  public void testAbsent() {
    assertEquals(
        "Map.merge(absent, value, function) should return value",
        v3(),
        getMap()
            .merge(
                k3(),
                v3(),
                (oldV, newV) -> {
                  throw new AssertionFailedError(
                      "Should not call merge function if key was absent");
                }));
    expectAdded(e3());
  }