ECL0105=Rethrew {0} as a runtime exception.
ECL0106=IOException occurred, because {0}
ECL0107=InvalidKeyException occurred, because {0}
ECL0108=The path is null.
ECL0109=Could not create a parent directory of {0}
ECL0110=A parent directory of {0} is not a directory.
ECL0111={0} is not a file.
ECL0112=Could not store {0}
ECL0113=NoSuchPaddingException occurred, because {0}
ECL0114=NoSuchAlgorithmException occurred, because {0}

///

/// note | "Technical Details"

You could also use `from starlette.requests import Request`.

**FastAPI** provides it as a convenience for you, the developer. But it comes directly from Starlette.

///

### Before and after the `response`

the current user is joined to a slow domain, which is the
usual case for many corporate users. The new implementation
performance is now in the order of milliseconds, compared to
the previous implementation which could take several seconds,

	for _, m := range mfs {
		if m.GetKind() == "ValidatingWebhookConfiguration" {
			validatingWebhookYAML = m.Content
			break
		}
	}
	if validatingWebhookYAML == "" {
		return "", fmt.Errorf("could not find ValidatingWebhookConfiguration in manifests")
	}

	scheme := runtime.NewScheme()
	codecFactory := serializer.NewCodecFactory(scheme)
	deserializer := codecFactory.UniversalDeserializer()

     *
     * - Any kind of Error from a listener. Even if we could distinguish that case (by exposing some
     * extra state from AbstractFuture), our options are limited: A call to setException() would be
     * a no-op. We could log, but if that's what we really want, we should modify
     * AbstractFuture.executeListener to do so, since that method would have the ability to continue
     * to execute other listeners.
     *

        MAX_FD=$( ulimit -H -n ) ||
            warn "Could not query maximum file descriptor limit"
    esac
    case $MAX_FD in  #(
      '' | soft) :;; #(
      *)
        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
        # shellcheck disable=SC2039,SC3045
        ulimit -n "$MAX_FD" ||
            warn "Could not set maximum file descriptor limit to $MAX_FD"
    esac
fi

    return backingMap;
  }

  @SuppressWarnings("unchecked") // value could not get in if not a T
  @CheckForNull
  private <T extends B> T trustedPut(TypeToken<@NonNull T> type, @ParametricNullness T value) {
    return (T) backingMap.put(type, value);
  }

  @SuppressWarnings("unchecked") // value could not get in if not a T
  @CheckForNull
  private <T extends @NonNull B> T trustedGet(TypeToken<T> type) {

        Node node = doResolve(link, classMetaData, listener);
        if (node != null) {
            return node;
        }

        listener.warning(String.format("Could not convert Javadoc link '%s'", link));
        Element element = document.createElement("UNHANDLED-LINK");
        element.appendChild(document.createTextNode(link));
        return element;
    }

For example, you could want to **return a dictionary** or a database object, but **declare it as a Pydantic model**. This way the Pydantic model would do all the data documentation, validation, etc. for the object that you returned (e.g. a dictionary or database object).

### Import `APIRouter`

You import it and create an "instance" the same way you would with the class `FastAPI`:

```Python hl_lines="1  3" title="app/routers/users.py"
{!../../docs_src/bigger_applications/app/routers/users.py!}
```

### *Path operations* with `APIRouter`

And then you use it to declare your *path operations*.

Use it the same way you would use the `FastAPI` class: