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

                        return true;
                    }
                    String packageName = getPackageName(file);
                    // we pass through package-info.java files for packages we have not seen before, block the rest
                    boolean notSeeBefore = packagesSeenBefore.add(packageName);
                    if (notSeeBefore) {
                        canonicalPackageInfos.add(file.getAbsoluteFile());

   * Sets {@code table[index]} to {@code entry}, where {@code table} is actually a {@code byte[]},
   * {@code short[]}, or {@code int[]}. The value of {@code entry} should fit in the size of the
   * assigned array element, when seen as an unsigned value. So if {@code table} is a {@code byte[]}
   * then we should have {@code 0 ≤ entry ≤ 255}, and if {@code table} is a {@code short[]} then we

### Conventions

Once a new property has been introduced, you need to consider what its conventions will be.

// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package cmd

import (
	"fmt"
	"maps"
	"sync"
	"sync/atomic"
	"time"

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".

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.

<img src="/img/tutorial/path-operation-advanced-configuration/image01.png">

And if you see the resulting OpenAPI (at `/openapi.json` in your API), you will see your extension as part of the specific *path operation* too:

```JSON hl_lines="22"
{
    "openapi": "3.1.0",
    "info": {
        "title": "FastAPI",

// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package grid

import (
	"context"
	"errors"
	"fmt"
	"sync"
	"sync/atomic"

   * errors, for better performance.
   *
   * <p>For a new instance, where the arrays above have not yet been allocated, the value of {@code
   * metadata} is the size that the arrays should be allocated with. Once the arrays have been
   * allocated, the value of {@code metadata} combines the number of bits in the "short hash", in