} else {
        return state;
      }
    }

    /** @see Service#failureCause() */
    Throwable failureCause() {
      checkState(
          state == FAILED,
          "failureCause() is only valid if the service has failed, service is %s",
          state);
      // requireNonNull is safe because the constructor requires a non-null cause with state=FAILED.
      return requireNonNull(failure);
    }
  }

```JSON
{
    "detail": [
        {
            "loc": [
                "path",
                "item_id"
            ],
            "msg": "value is not a valid integer",
            "type": "type_error.integer"
        }
    ]
}
```

これは、パスパラメータ `item_id` が `int` ではない値 `"foo"` だからです。

                ssn.removeAttribute("npa-" + server);
            }
            if ( sae.getNtStatus() == NtStatus.NT_STATUS_ACCESS_VIOLATION ) {
                /*
                 * Server challenge no longer valid for
                 * externally supplied password hashes.
                 */
                resp.sendRedirect(req.getRequestURL().toString());
                return;
            }

  // Spec for the ResourceClaim. The entire content is copied unchanged
  // into the ResourceClaim that gets created from this template. The
  // same fields as in a ResourceClaim are also valid here.
  optional ResourceClaimSpec spec = 2;
}

// ResourceClass is used by administrators to influence how resources
// are allocated.
//

            if( ssn != null ) {
                ssn.removeAttribute( "npa-" + server );
            }
            if( sae.getNtStatus() == sae.NT_STATUS_ACCESS_VIOLATION ) {
                /* Server challenge no longer valid for
                 * externally supplied password hashes.
                 */
                resp.sendRedirect( req.getRequestURL().toString() );
                return;
            }

      assertTrue(
          IntMath.biggestBinomials[k] == Integer.MAX_VALUE
              || !fitsInInt(BigIntegerMath.binomial(IntMath.biggestBinomials[k] + 1, k)));
      // In the first case, any int is valid; in the second, we want to test that the next-bigger
      // int overflows.
    }
    assertFalse(
        fitsInInt(
            BigIntegerMath.binomial(

...y con esa única declaración obtienes:

* Soporte del editor incluyendo:
    * Auto completado.
    * Anotaciones de tipos.
* Validación de datos:
    * Errores automáticos y claros cuándo los datos son inválidos.
    * Validación, incluso para objetos JSON profundamente anidados.
* <abbr title="en inglés: serialization, parsing, marshalling">Conversión</abbr> de datos de input: viniendo de la red a datos y tipos de Python. Leyendo desde:

```Python
say_hi()  # Oh, no, this throws an error! 😱
```

`name` 🔢 **✔** (🚫 *📦*) ↩️ ⚫️ 🚫 ✔️ 🔢 💲. , `name` 🚫 `None` 💲:

```Python
say_hi(name=None)  # This works, None is valid 🎉
```

👍 📰, 🕐 👆 🔛 🐍 3️⃣.1️⃣0️⃣ 👆 🏆 🚫 ✔️ 😟 🔃 👈, 👆 🔜 💪 🎯 ⚙️ `|` 🔬 🇪🇺 🆎:

```Python hl_lines="1  4"
{!../../docs_src/python_types/tutorial009c_py310.py!}
```

    state.addListener(listener, executor);
  }

  /**
   * Initiates service {@linkplain Service#startAsync startup} on all the services being managed. It
   * is only valid to call this method if all of the services are {@linkplain State#NEW new}.
   *
   * @return this
   * @throws IllegalStateException if any of the Services are not {@link State#NEW new} when the
   *     method is called.

    state.addListener(listener, executor);
  }

  /**
   * Initiates service {@linkplain Service#startAsync startup} on all the services being managed. It
   * is only valid to call this method if all of the services are {@linkplain State#NEW new}.
   *
   * @return this
   * @throws IllegalStateException if any of the Services are not {@link State#NEW new} when the
   *     method is called.