* The response `418`. 🍵

But that will only affect that `APIRouter` in our app, not in any other code that uses it.

So, for example, other projects could use the same `APIRouter` with a different authentication method.

### Include a *path operation*

We can also add *path operations* directly to the `FastAPI` app.

Here we do it... just to show that we can 🤷:

```Python hl_lines="21-23" title="app/main.py"

      // before the cancelled future completes, it will synchronously complete both the newFuture
      // from the cancelled operation and its own. This can cause one runnable to queue two tasks,
      // breaking the invariant this method relies on to iteratively run the next task after the
      // previous one completes.
      if (get() == RunningState.CANCELLED) {
        delegate = null;
        sequencer = null;
        return;
      }

import junit.framework.TestCase;

/**
 * Tests for {@link StatsAccumulator}. This tests the stats methods for instances built with {@link
 * StatsAccumulator#add} and {@link StatsAccumulator#addAll}, and various error cases of the {@link
 * StatsAccumulator#add} and {@link StatsAccumulator#addAll} methods. For tests of the {@link
 * StatsAccumulator#snapshot} method which returns {@link Stats} instances, see {@link StatsTest}.
 *
 * @author Pete Gillin
 */

    }

    /**
     * We are interested in project success events, in which case we call
     * the {@link #installIntoProjectLocalRepository(MavenProject)} method.
     * The mojo started event is also captured to determine the lifecycle
     * phases the project has been through.
     *
     * @param event the execution event
     */

			return
		}
	}

	tx.Statement.Joins = append(tx.Statement.Joins, join{Name: query, Conds: args, JoinType: joinType})
	return
}

// Group specify the group method on the find
//
//	// Select the sum age of users with given names
//	db.Model(&User{}).Select("name, sum(age) as total").Group("name").Find(&results)
func (db *DB) Group(name string) (tx *DB) {
	tx = db.getInstance()

```Python hl_lines="6"
{!../../docs_src/first_steps/tutorial001.py!}
```

`@app.get("/")` nói **FastAPI** rằng hàm bên dưới có trách nhiệm xử lí request tới:

* đường dẫn `/`
* sử dụng một <abbr title="an HTTP GET method">toán tử<code>get</code></abbr>

/// info | Thông tin về "`@decorator`"

Cú pháp `@something` trong Python được gọi là một "decorator".

	MessageWriter:     os.Stdout,
	XdsViaAgents:      false,
	XdsViaAgentsLimit: 0,
}

// RequestAndProcessXds merges XDS responses from 1 central or 1..N K8s cluster-based XDS servers
// Deprecated This method makes multiple responses appear to come from a single control plane;
// consider using AllRequestAndProcessXds or FirstRequestAndProcessXds
// nolint: lll

    /** a flag to trim a space characters. */
    protected boolean trimSpaceEnabled = true;

    protected String charsetName = Constants.UTF_8;

    /**
     * Class type returned by getData() method. The default is null(XML content
     * of String).
     */
    protected Class<?> dataClass = null;

    protected LoadingCache<String, XPathAPI> xpathAPICache;

    protected long cacheDuration = 10; // min

          }
        }
      }
    },
    /*
     * This one comes last to work around b/367716565. (One *possible* alternative would be to not
     * declare any methods in this enum, converting assertFailsToDecode into a static method that is
     * implemented with a `switch`. I haven't tested that.)
     */
    @GwtIncompatible // decodingStream(Reader)
    DECODING_STREAM {
      @Override

	// refer to ast2 instead.
	f.walk(ast1, ctxProg, (*File).saveExport)
	f.walk(ast2, ctxProg, (*File).saveExport2)

	f.Comments = ast1.Comments
	f.AST = ast2
}

// Like ast.CommentGroup's Text method but preserves
// leading blank lines, so that line numbers line up.
func commentText(g *ast.CommentGroup) string {
	pieces := make([]string, 0, len(g.List))
	for _, com := range g.List {
		c := com.Text