final class Platform {

  private static final char[] CHAR_BUFFER = new char[1024];

  static char[] charBufferFromThreadLocal() {
    // ThreadLocal is not available to GWT, so we always reuse the same
    // instance.  It is always safe to return the same instance because
    // javascript is single-threaded, and only used by blocks that doesn't
    // involve async callbacks.
    return CHAR_BUFFER;
  }

  private Platform() {}

        // Should be the same instance
        assertSame(status1, status2);
        assertTrue(status1 == status2);

        // valueOf should return the same instance
        CrawlerStatus status3 = CrawlerStatus.valueOf("INITIALIZING");
        assertSame(status1, status3);
        assertTrue(status1 == status3);

        // values() array contains the same instances

    }

    // Because we happen to use the same formula. If that changes, just don't override this.
    @Override
    public int hashCode() {
      return parent.hashCode();
    }

    @Override
    public String toString() {
      return parent.toString();
    }
  }

  /**
   * Returns {@code true} if {@code object} is an {@code ImmutableLongArray} containing the same
   * values as this one, in the same order.

    }

    // Because we happen to use the same formula. If that changes, just don't override this.
    @Override
    public int hashCode() {
      return parent.hashCode();
    }

    @Override
    public String toString() {
      return parent.toString();
    }
  }

  /**
   * Returns {@code true} if {@code object} is an {@code ImmutableIntArray} containing the same
   * values as this one, in the same order.

    }

    @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);

<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*:

   */
  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

   * this {@code Joiner} otherwise.
   *
   * @since 20.0
   */
  public MapJoiner withKeyValueSeparator(char keyValueSeparator) {
    return withKeyValueSeparator(String.valueOf(keyValueSeparator));
  }

  /**
   * Returns a {@code MapJoiner} using the given key-value separator, and the same configuration as
   * this {@code Joiner} otherwise.

# 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**.