b.off += n
	b.lastRead = readOp(n)
	return r, n, nil
}

// UnreadRune unreads the last rune returned by [Buffer.ReadRune].
// If the most recent read or write operation on the buffer was
// not a successful [Buffer.ReadRune], UnreadRune returns an error.  (In this regard
// it is stricter than [Buffer.UnreadByte], which will unread the last byte
// from any read operation.)
func (b *Buffer) UnreadRune() error {

**FastAPI** is all based on these type hints, they give it many advantages and benefits.

But even if you never use **FastAPI**, you would benefit from learning a bit about them.

/// note

If you are a Python expert, and you already know everything about type hints, skip to the next chapter.

///

## Motivation

Let's start with a simple example:

{* ../../docs_src/python_types/tutorial001.py *}

Calling this program outputs:

		if !containerStatus.Ready {
			fmt.Fprintf(writer, "WARNING: Pod %s Container %s NOT READY\n", kname(pod.ObjectMeta), containerStatus.Name)
		}
	}
	for _, containerStatus := range pod.Status.InitContainerStatuses {
		if !containerStatus.Ready {
			fmt.Fprintf(writer, "WARNING: Pod %s Init Container %s NOT READY\n", kname(pod.ObjectMeta), containerStatus.Name)
		}
	}

  }

  /**
   * Starts the stopwatch.
   *
   * @return this {@code Stopwatch} instance
   * @throws IllegalStateException if the stopwatch is already running.
   */
  @CanIgnoreReturnValue
  public Stopwatch start() {
    checkState(!isRunning, "This stopwatch is already running.");
    isRunning = true;
    startTick = ticker.read();
    return this;
  }

  /**

But we want to be able to parameterize that fixed content.

## A "callable" instance

In Python there's a way to make an instance of a class a "callable".

Not the class itself (which is already a callable), but an instance of that class.

To do that, we declare a method `__call__`:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[12] *}

public interface LifecycleBindingsInjector {

    /**
     * Injects plugin executions induced by lifecycle bindings into the specified model. The model has already undergone
     * injection of plugin management so any plugins that are injected by lifecycle bindings and are not already present
     * in the model's plugin section need to be subjected to the model's plugin management.
     *

				t.Fatalf("n = %d: incorrect byte returned from ReadByte: got %q, want %q", n, b, data[i])
			}
		}
		// Unread one byte if there is one.
		if n > 0 {
			if err := r.UnreadByte(); err != nil {
				t.Errorf("n = %d: unexpected error on UnreadByte: %v", n, err)
			}
		}
		// Test that we cannot unread any further.
		if err := r.UnreadByte(); err == nil {
			t.Errorf("n = %d: expected error on UnreadByte", n)
		}
	}

You will see the JSON response as:

```JSON
{"item_id": 5, "q": "somequery"}
```

You already created an API that:

* Receives HTTP requests in the _paths_ `/` and `/items/{item_id}`.
* Both _paths_ take `GET` operations (also known as HTTP _methods_).

      // elements already available (e.g. LinkedBlockingQueue#drainTo locks only once)
      added += q.drainTo(buffer, numElements - added);
      if (added < numElements) { // not enough elements immediately available; will have to poll
        E e = q.poll(deadline - System.nanoTime(), NANOSECONDS);
        if (e == null) {
          break; // we already waited enough, and there are no more elements in sight

  }

  /**
   * Must be called at the end of each subclass's constructor. This method performs the "real"
   * initialization; we can't put this in the constructor because, in the case where futures are
   * already complete, we would not initialize the subclass before calling {@link
   * #collectValueFromNonCancelledFuture}. As this is called after the subclass is constructed,
   * we're guaranteed to have properly initialized the subclass.