}

    @Test
    @DisplayName("Should produce consistent keys for same input")
    void testDeriveKeys_Consistency() {
        // Given
        int dialect = Smb2Constants.SMB2_DIALECT_0311;

        // When - derive same key twice
        byte[] signingKey1 = Smb3KeyDerivation.deriveSigningKey(dialect, sessionKey, preauthIntegrity);

        TestSpnegoToken t = new TestSpnegoToken();
        byte[] raw = new byte[] { 11, 12, 13 };
        t.parse(raw);
        // Current behavior of test impl: returns same reference
        assertSame(raw, t.toByteArray(), "should return the same reference as mechanismToken");
    }

    @Test
    @DisplayName("Setters accept null and getters return null")
    void settersAcceptNull() {

<img src="/img/tutorial/websockets/image04.png">

And all of them will use the same WebSocket connection.

## Using `Depends` and others { #using-depends-and-others }

In WebSocket endpoints you can import from `fastapi` and use:

* `Depends`
* `Security`
* `Cookie`
* `Header`
* `Path`
* `Query`

They work the same way as for other FastAPI endpoints/*path operations*:

Import `BaseSettings` from Pydantic and create a sub-class, very much like with a Pydantic model.

The same way as with Pydantic models, you declare class attributes with type annotations, and possibly default values.

You can use all the same validation features and tools you use for Pydantic models, like different data types and additional validations with `Field()`.

//// tab | Pydantic v2

/**
 * A subscriber method on a specific object, plus the executor that should be used for dispatching
 * events to it.
 *
 * <p>Two subscribers are equivalent when they refer to the same method on the same object (not
 * class). This property is used to ensure that no subscriber method is registered more than once.
 *
 * @author Colin Decker
 */
class Subscriber {

   */
  public final FluentIterable<E> skip(int numberToSkip) {
    return from(Iterables.skip(getDelegate(), numberToSkip));
  }

  /**
   * Creates a fluent iterable with the first {@code size} elements of this fluent iterable. If this
   * fluent iterable does not contain that many elements, the returned fluent iterable will have the

   */
  public final FluentIterable<E> skip(int numberToSkip) {
    return from(Iterables.skip(getDelegate(), numberToSkip));
  }

  /**
   * Creates a fluent iterable with the first {@code size} elements of this fluent iterable. If this
   * fluent iterable does not contain that many elements, the returned fluent iterable will have the

# Security - First Steps { #security-first-steps }

Let's imagine that you have your **backend** API in some domain.

And you have a **frontend** in another domain or in a different path of the same domain (or in a mobile application).

And you want to have a way for the frontend to authenticate with the backend, using a **username** and **password**.

We can use **OAuth2** to build that with **FastAPI**.

The parameter `summary` is available in OpenAPI 3.1.0 and above, supported by FastAPI 0.99.0 and above.

///

## Overriding the defaults { #overriding-the-defaults }

Using the information above, you can use the same utility function to generate the OpenAPI schema and override each part that you need.

   * exactly one entry for each distinct element in the multiset (thus it always has the same size
   * as the {@link #elementSet}). The order of the elements in the element set is unspecified.
   *
   * <p>The entry set is backed by the same data as the multiset, so any change to either is
   * immediately reflected in the other. However, multiset changes may or may not be reflected in