The exception handler will receive a `Request` and the exception.

```Python hl_lines="2  14-16"
{!../../docs_src/handling_errors/tutorial004.py!}
```

Now, if you go to `/items/foo`, instead of getting the default JSON error with:

```JSON
{
    "detail": [
        {
            "loc": [
                "path",
                "item_id"
            ],

    response = client.post(
        "/admin/?token=jessica", headers={"X-Token": "fake-super-secret-token"}
    )
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Admin getting schwifty"}


def test_admin_invalid_header(client: TestClient):
    response = client.post("/admin/", headers={"X-Token": "invalid"})
    assert response.status_code == 400, response.text

  /**
   * Views the array as an immutable list. The array must have only {@code E} elements.
   *
   * <p>The array must be internally created.
   */
  @SuppressWarnings("unchecked") // caller is reponsible for getting this right
  static <E> ImmutableList<E> asImmutableList(Object[] elements) {
    return unsafeDelegateList((List) Arrays.asList(elements));
  }

## Враження

"_[...] I'm using **FastAPI** a ton these days. [...] I'm actually planning to use it for all of my team's **ML services at Microsoft**. Some of them are getting integrated into the core **Windows** product and some **Office** products._"

            + (throwable == null ? null : Throwables.getStackTraceAsString(throwable)),
        throwableFromOtherThread.get());
  }

  /**
   * Test for a bug where threads weren't getting signaled when shutdown was called, only when tasks
   * completed.
   */
  public void testDirectExecutorService_awaitTermination_missedSignal() {
    final ExecutorService service = newDirectExecutorService();

   * requests become more likely to trigger expensive operations (a more extreme case of this
   * example is when a server has just booted, and it is mostly busy with getting itself up to
   * speed).
   *
   * To deal with such scenarios, we add an extra dimension, that of "past underutilization",
   * modeled by "storedPermits" variable. This variable is zero when there is no underutilization,

// already-finalized operation.
//
// Note that TFE_OpGetFlatInputCount and TFE_OpGetFlatInput operate on a flat
// sequence of inputs, unlike TFE_OpGetInputLength (for getting the length of a
// particular named input list, which may only be part of the op's inputs).
TF_CAPI_EXPORT extern int TFE_OpGetFlatInputCount(const TFE_Op* op,
                                                  TF_Status* status);

 |                 NOTE: This location can be overridden with the CLI option:
 |
 |                 -is /path/to/installation/settings.xml
 |
 | The sections in this sample file are intended to give you a running start at
 | getting the most out of your Maven installation. Where appropriate, the default
 | values (values used when the setting is not specified) are provided.
 |
 |-->
<settings xmlns="http://maven.apache.org/SETTINGS/2.0.0"

   * our class loader (which could be that of a dynamically loaded web application or OSGi bundle),
   * it would prevent our class loader from getting garbage collected.
   */
  static class DecoupledLoader implements FinalizerLoader {
    private static final String LOADING_ERROR =

    try {
      // We get the result, even if collectOneValue is a no-op, so that we can fail fast.
      // We use getUninterruptibly over getDone as a micro-optimization, we know the future is done.
      collectOneValue(index, getUninterruptibly(future));
    } catch (ExecutionException e) {
      handleException(e.getCause());