final Iterator<String> it = new MultiIterator<String>(list1.iterator(), list2.iterator());

        assertThat(it.hasNext(), is(true));
        assertThat(it.next(), is("Foo"));

        assertThat(it.hasNext(), is(true));
        assertThat(it.next(), is("Bar"));

        assertThat(it.hasNext(), is(true));
        assertThat(it.next(), is("Baz"));

        assertThat(it.hasNext(), is(not(true)));
    }

                    FunctionalTestBucket(it).toBuildTypeBucket(model.subprojects)
                }

            // Sometimes people may add new subproject into `subprojects.json`
            // in this case we have no historical test running time, so we simply add these subprojects into first available bucket
            val allSubprojectsInBucketJson = buckets.flatMap { it.subprojects.map { it.name } }.toSet()

In the case of our dependency `get_settings()`, the function doesn't even take any arguments, so it always returns the same value.

That way, it behaves almost as if it was just a global variable. But as it uses a dependency function, then we can override it easily for testing.

If you declare it as is, because it is a singular value, **FastAPI** will assume that it is a query parameter.

But you can instruct **FastAPI** to treat it as another body key using `Body`:

{* ../../docs_src/body_multiple_params/tutorial003_an_py310.py hl[23] *}

    private val includePackagePatterns: List<Pattern> by lazy {
        includes.map {
            if (it.endsWith("/**")) {
                Pattern.compile(it.substring(0, it.length - 3).replace("/", "\\.") + "(\\..+)?")
            } else {
                Pattern.compile(it.substring(0, it.length - 2).replace("/", "\\.") + "\\.[^.]+")
            }
        }
    }

 of this license document, but changing it is not allowed.

(This is the first released version of the Lesser GPL.  It also counts
 as the successor of the GNU Library Public License, version 2, hence
 the version number 2.1.)

                            Preamble

  The licenses for most software are designed to take away your
freedom to share and change it.  By contrast, the GNU General Public

          stale-pr-label: stale
          stale-pr-message: >
            This pull request has been automatically marked as stale because it has not had recent activity.
            It will be closed in 14 days if no further activity occurs.
            If you don't want the stale bot to close it, then set a milestone for it.
          days-before-pr-close: 14
          close-pr-message: >

# WebSockets

When defining WebSockets, you normally declare a parameter of type `WebSocket` and with it you can read data from the client and send data to it.

It is provided directly by Starlette, but you can import it from `fastapi`:

```python
from fastapi import WebSocket
```

/// tip

* Add a **JSON Schema** for the response, in the OpenAPI *path operation*.
    * This will be used by the **automatic docs**.

Since **Pydantic v2** was released, the generated OpenAPI is a bit more exact and **correct** than before. 😎

In fact, in some cases, it will even have **two JSON Schemas** in OpenAPI for the same Pydantic model, for input and output, depending on if they have **default values**.

Let's see how that works and how to change it if you need to do that.

## Pydantic Models for Input and Output { #pydantic-models-for-input-and-output }