*
   * <p>After calling this method, you may not call {@link #finishToFuture()}, {@link
   * #finishToValueAndCloser(ValueAndCloserConsumer, Executor)}, or any other derivation method on
   * the original {@code ClosingFuture} instance.
   *
   * @param function transforms the value of this step to the value of the derived step
   * @param executor executor to run the function in
   * @return the derived step

        VersionRange range2 = VersionRange.createFromVersionSpec("1.1");
        VersionRange mergedRange = range1.restrict(range2);
        // TODO current policy is to retain the original version - is this correct, do we need strategies or is that
        // handled elsewhere?
        //        assertEquals( "1.1", mergedRange.getRecommendedVersion().toString(), CHECK_VERSION_RECOMMENDATION );

## Technische Details

Moderne Versionen von Python unterstützen **„asynchronen Code“** unter Verwendung sogenannter **„Coroutinen“** mithilfe der Syntax **`async`** und **`await`**.

Nehmen wir obigen Satz in den folgenden Abschnitten Schritt für Schritt unter die Lupe:

* **Asynchroner Code**
* **`async` und `await`**
* **Coroutinen**

## Asynchroner Code

En este caso, el path original `/app` realmente sería servido en `/api/v1/app`.

Aunque todo tu código esté escrito asumiendo que solo existe `/app`.

{* ../../docs_src/behind_a_proxy/tutorial001.py hl[6] *}

   * subsequent cycles omit the removed element, but {@code elements} does not change. The
   * iterator's {@code hasNext()} method returns {@code true} until all of the original elements
   * have been removed.
   *
   * <p><b>Warning:</b> Typical uses of the resulting iterator may produce an infinite loop. You

   *
   * <p>The {@link Table#cellSet()} iteration order of the provided table determines the iteration
   * ordering of all views in the returned table. Note that some views of the original table and the
   * copied table may have different iteration orders. For more control over the ordering, create a
   * {@link Builder} and call {@link Builder#orderRowsBy}, {@link Builder#orderColumnsBy}, and

		n += int64(m)
		if e == io.EOF {
			return n, nil // e is EOF, so return nil explicitly
		}
		if e != nil {
			return n, e
		}
	}
}

// growSlice grows b by n, preserving the original content of b.
// If the allocation fails, it panics with ErrTooLarge.
func growSlice(b []byte, n int) []byte {
	defer func() {
		if recover() != nil {
			panic(ErrTooLarge)
		}
	}()

   * as bytes using the given {@link Charset}.
   *
   * <p>If {@link ByteSource#asCharSource} is called on the returned source with the same charset,
   * the default implementation of this method will ensure that the original {@code CharSource} is
   * returned, rather than round-trip encoding. Subclasses that override this method should behave
   * the same way.
   *
   * @since 20.0
   */

   * as bytes using the given {@link Charset}.
   *
   * <p>If {@link ByteSource#asCharSource} is called on the returned source with the same charset,
   * the default implementation of this method will ensure that the original {@code CharSource} is
   * returned, rather than round-trip encoding. Subclasses that override this method should behave
   * the same way.
   *
   * @since 20.0
   */

If you catch an exception in a dependency with `yield`, unless you are raising another `HTTPException` or similar, you should re-raise the original exception.

You can re-raise the same exception using `raise`:

{* ../../docs_src/dependencies/tutorial008d_an_py39.py hl[17] *}