"Error while attempting to shut down the service after failure.",
                    ignored);
          }
          notifyFailed(t);
          // requireNonNull is safe now, just as it was above.
          requireNonNull(runningTask).cancel(false); // prevent future invocations.
        } finally {
          lock.unlock();
        }
      }
    }

     * These methods "should" call checkNotNull. However, I'm wary of accidentally introducing
     * anything that might slow down execution on such a hot path. Given that the methods are only
     * package-private, I feel OK with just not testing them for NPE.
     *
     * Note that testing casValue is particularly dangerous because it uses Unsafe under some
     * versions of Java, and apparently Unsafe can cause SIGSEGV instead of NPE—almost as if it's

        // artificial restriction and require that when num_opers=-1, such
        // nodes must have a single output.
        if (node->num_outputs() != 1) {
          return InvalidArgument(
              "When `num_opers` is set to -1, nodes referenced in `inputs` "
              "must have a single output. Node ",
              node->name(), " has ", node->num_outputs(),

![ReDoc](https://fastapi.tiangolo.com/img/index/index-06-redoc-02.png)

### Nur modernes Python { #just-modern-python }

Alles basiert auf Standard-**Python-Typ**deklarationen (dank Pydantic). Es muss keine neue Syntax gelernt werden, nur standardisiertes modernes Python.

You do that with standard modern Python types.

You don't have to learn a new syntax, the methods or classes of a specific library, etc.

Just standard **Python**.

For example, for an `int`:

```Python
item_id: int
```

or for a more complex `Item` model:

```Python
item: Item
```

          <version>4.0.0+</version>
          <description>
            <![CDATA[
            Just like {@code connection}, but for developers, i.e. this scm connection
            will not be read only.
            <p><b>Default value is</b>: parent value [+ path adjustment] + (artifactId or project.directory property), or just parent value if
            scm's {@code child.scm.developerConnection.inherit.append.path="false"}.</p>

Node selectors (to constrain pods to schedule on a subset of nodes) now support
the operators {<code>In, NotIn, Exists, DoesNotExist, Gt, Lt</code>}  instead of just conjunction of exact match on node label values. In
addition, we’ve introduced a new “soft” kind of node selector that is just a
hint to the scheduler; the scheduler will try to satisfy these requests but it
does not guarantee they will be satisfied. Both the “hard” and “soft” variants

     */
    private static Class<?> loadImplementation(final String name, final Class<?> defaultClazz) {
        if (null == name) {
            return defaultClazz; // just use the default type
        }

        // TCCL allows surrounding container to influence class loading policy
        final ClassLoader tccl = Thread.currentThread().getContextClassLoader();
        if (tccl != null) {

![ReDoc](https://fastapi.tiangolo.com/img/index/index-06-redoc-02.png)

### Apenas Python moderno { #just-modern-python }

Tudo é baseado no padrão das declarações de **tipos do Python** (graças ao Pydantic). Nenhuma sintaxe nova para aprender. Apenas o padrão moderno do Python.

**FastAPI** generates a "schema" with all your API using the **OpenAPI** standard for defining APIs.

#### "Schema" { #schema }

A "schema" is a definition or description of something. Not the code that implements it, but just an abstract description.

#### API "schema" { #api-schema }