# scripts. By setting "expand_aliases", we enable alias expansion in
  # non-interactive shells as well.
  shopt -s expand_aliases
else
  echo '==TFCI==: Error: Cannot find path to grealpath or gstat'
  echo 'TF CI scripts require GNU core utilties to be installed. Please make'
  echo 'sure they are present on your system and try again.'
  exit 1
fi

testing everything. You can even copy & paste HTTP responses from your real web
server to create representative test cases. Or test that your code survives in
awkward-to-reproduce situations like 500 errors or slow-loading responses.


### Example

Use MockWebServer the same way that you use mocking frameworks like
[Mockito](https://github.com/mockito/mockito):

1. Script the mocks.
2. Run application code.

     */
    @Nullable
    XmlNode child(String name);

    /**
     * Returns the input location information for this node, if available.
     * This can be useful for error reporting and debugging.
     *
     * @return the input location object, or {@code null} if not available
     */
    @Nullable
    Object inputLocation();

    // Deprecated methods that delegate to new ones

     * Creates a session ID, sets up the execution environment, and runs the Python script
     * with the configured filename and arguments.
     *
     * @return a string containing the execution result and any error messages
     */
    @Override
    public String execute() {
        final StringBuilder resultBuf = new StringBuilder();

        if (sessionId == null) { // create session id

                log.trace("Got subject " + s);
            }

            this.cachedSubject = s;
            return this.cachedSubject;
        } catch (LoginException e) {
            log.error("Failed to create login context", e);
            // Cache null to ensure consistent behavior across calls
            this.cachedSubject = null;
            return null;
        }
    }

    /**

app = SomeASGIApp()

new_app = UnicornMiddleware(app, some_config="rainbow")
```

Pero FastAPI (en realidad Starlette) proporciona una forma más simple de hacerlo que asegura que los middlewares internos manejen errores del servidor y los controladores de excepciones personalizadas funcionen correctamente.

Para eso, usas `app.add_middleware()` (como en el ejemplo para CORS).

```Python
from fastapi import FastAPI

                                            <la:option value="OFF">OFF</la:option>
                                            <la:option value="FATAL">FATAL</la:option>
                                            <la:option value="ERROR">ERROR</la:option>
                                            <la:option value="WARN">WARN</la:option>
                                            <la:option value="INFO">INFO</la:option>

  private static final String E44 = "4-4";
  private static final int NODE_COUNT = 20;
  private static final int EDGE_COUNT = 20;
  // TODO(user): Consider adding both error messages from here and {@link AbstractNetworkTest}
  // in one class (may be a utility class for error messages).
  private static final String ERROR_PARALLEL_EDGE = "connected by a different edge";
  private static final String ERROR_NEGATIVE_COUNT = "is non-negative";

* **Validar** los datos devueltos.
    * Si los datos son inválidos (por ejemplo, falta un campo), significa que el código de *tu* aplicación está defectuoso, no devolviendo lo que debería, y retornará un error del servidor en lugar de devolver datos incorrectos. De esta manera, tú y tus clientes pueden estar seguros de que recibirán los datos y la forma de los datos esperada.

            }

            bufferIndex += e.nextEntryOffset;
        }

        /* last nextEntryOffset for NT 4(but not 98) is 0 so we must
         * use dataCount or our accounting will report an error for NT :~(
         */

        //return bufferIndex - start;

        return dataCount;
    }

    @Override
    public String toString() {
        String c;