Two new interfaces, [TextAppender] and [BinaryAppender], have been
introduced to append the textual or binary representation of an object
to a byte slice. These interfaces provide the same functionality as
[TextMarshaler] and [BinaryMarshaler], but instead of allocating a new slice

```Python hl_lines="5-6"
{!../../docs_src/dependencies/tutorial007.py!}
```

/// tip

You can use `async` or regular functions.

**FastAPI** will do the right thing with each, the same as with normal dependencies.

///

## A dependency with `yield` and `try`

If you use a `try` block in a dependency with `yield`, you'll receive any exception that was thrown when using the dependency.

### Multiple Applications

In the same server (or servers), there could be **multiple applications**, for example, other API programs or a database.

Only one process can be handling the specific IP and port (the TLS Termination Proxy in our example) but the other applications/processes can be running on the server(s) too, as long as they don't try to use the same **combination of public IP and port**.

import org.opentest4j.TestAbortedException

/**
 * This test binds two different web servers (IPv4 and IPv6) to the same port, but on different
 * local IP addresses. Requests made to `127.0.0.1` will reach the IPv4 server, and requests made to
 * `::1` will reach the IPv6 server.
 *
 * By orchestrating two different servers with the same port but different IP addresses, we can
 * test what OkHttp does when both are reachable, or if only one is reachable.

        final String key = fessConfig.getSystemProperty("saml.attribute.group.name", "memberOf");
        if (StringUtil.isNotBlank(key)) {
            final List<String> nameList = attributes.get(key);
            if (nameList != null) {
                list.addAll(nameList);
            }
        }
        final String value = fessConfig.getSystemProperty("saml.default.groups");
        if (StringUtil.isNotBlank(value)) {

   * same order. (It is guaranteed to return true for instances constructed from the same values in
   * the same order if {@code strictfp} is in effect, or if the system architecture guarantees
   * {@code strictfp}-like semantics.)
   */
  @Override
  public boolean equals(@CheckForNull Object obj) {
    if (obj == null) {
      return false;
    }
    if (getClass() != obj.getClass()) {
      return false;
    }

# Extra Data Types

Up to now, you have been using common data types, like:

* `int`
* `float`
* `str`
* `bool`

But you can also use more complex data types.

And you will still have the same features as seen up to now:

* Great editor support.
* Data conversion from incoming requests.
* Data conversion for response data.
* Data validation.
* Automatic annotation and documentation.

## Other data types

   *       (<i>symmetric</i> property)
   *   <li>If {@code equivalent(x, y)} and {@code equivalent(y, z)} are both true, then {@code
   *       equivalent(x, z)} is also true (<i>transitive</i> property)
   * </ul>
   *
   * <p>Note that all calls to {@code equivalent(x, y)} are expected to return the same result as
   * long as neither {@code x} nor {@code y} is modified.

    // enclosed with same start
    assertEquals(range, range.span(Range.closed(4, 6)));

    // enclosed, interior
    assertEquals(range, range.span(Range.closed(5, 7)));

    // enclosed with same end
    assertEquals(range, range.span(Range.closed(6, 8)));

    // equal
    assertEquals(range, range.span(range));

    // enclosing with same start

   * the URL's host name. Note that concurrent requests to a single IP address may still exceed this
   * limit: multiple hostnames may share an IP address or be routed through the same HTTP proxy.
   *
   * If more than [maxRequestsPerHost] requests are in flight when this is invoked, those requests
   * will remain in flight.
   *
   * WebSocket connections to hosts **do not** count against this limit.