We can do better...

## What makes a dependency { #what-makes-a-dependency }

Up to now you have seen dependencies declared as functions.

But that's not the only way to declare dependencies (although it would probably be the more common).

The key factor is that a dependency should be a "callable".

 * to create multiple escaper instances that have the same character replacement mapping consider
 * using {@link ArrayBasedEscaperMap}.
 *
 * @author Sven Mawson
 * @author David Beaumont
 * @since 15.0
 */
@GwtCompatible
public abstract class ArrayBasedCharEscaper extends CharEscaper {
  // The replacement array (see ArrayBasedEscaperMap).

There is no cancellation propagation for single payload requests.
When the context is canceled, the request will return at once with an appropriate error.
However, the remote call will not see the cancellation - as can be seen from the 'missing' context on the handler.
The result will be discarded.

### Typed handlers

Typed handlers are handlers that have a specific type for the request and response payloads.

{* ../../docs_src/path_operation_advanced_configuration/tutorial004_py310.py hl[17:27] *}

## Additional Responses { #additional-responses }

You probably have seen how to declare the `response_model` and `status_code` for a *path operation*.

That defines the metadata about the main response of a *path operation*.

like that curious song about the whiting!'

  `Oh, as to the whiting,' said the Mock Turtle, `they--you've
seen them, of course?'

  `Yes,' said Alice, `I've often seen them at dinn--' she
checked herself hastily.

  `I don't know where Dinn may be,' said the Mock Turtle, `but
if you've seen them so often, of course you know what they're
like.'

  `I believe so,' Alice replied thoughtfully.  `They have their

		case <-m.ctx.Done():
			return
		case <-t.C:
			last := time.Since(time.Unix(atomic.LoadInt64(&m.LastPing), 0))
			if last > 4*m.clientPingInterval {
				gridLogIf(m.ctx, fmt.Errorf("canceling remote connection %s not seen for %v", m.parent, last))
				m.close()
				return
			}
		}
	}
}

// checkSeq will check if sequence number is correct and increment it by 1.
func (m *muxServer) checkSeq(seq uint32) (ok bool) {

 * the return type. For this case, we provide a more expensive workaround in {@code
 * JdkFutureAdapters}. However, when possible, it is more efficient and reliable to create a {@code
 * ListenableFuture} directly.
 *
 * @author Sven Mawson
 * @author Nishant Thakkar
 * @since 1.0
 */
/*
 * Some of the annotations below were added after we released our separate
 * com.google.guava:listenablefuture:1.0 artifact. (For more on that artifact, see

 * the return type. For this case, we provide a more expensive workaround in {@code
 * JdkFutureAdapters}. However, when possible, it is more efficient and reliable to create a {@code
 * ListenableFuture} directly.
 *
 * @author Sven Mawson
 * @author Nishant Thakkar
 * @since 1.0
 */
/*
 * Some of the annotations below were added after we released our separate
 * com.google.guava:listenablefuture:1.0 artifact. (For more on that artifact, see

# Advanced Dependencies { #advanced-dependencies }

## Parameterized dependencies { #parameterized-dependencies }

All the dependencies we have seen are a fixed function or class.

But there could be cases where you want to be able to set parameters on the dependency, without having to declare many different functions or classes.

Let's imagine that we want to have a dependency that checks if the query parameter `q` contains some fixed content.

practice is to set conventions in a plugin (2). This keeps the underlying object "dumb", so it can be reused in multiple contexts and doesn't contain any special information about how conventions are calculated or what they could be.  In the wild, we've seen some objects set conventions in the object's constructor (3), but this can lead to unexpected assumptions or coupling between plugins.

For external plugins, it's difficult for an object to be used outside the application of a plugin, so...