/**
   * 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));
  }

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

{* ../../docs_src/handling_errors/tutorial004.py hl[2,14:16] *}

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

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

    // -----------------------------------------------------
    //                                            Entry Page
    //                                            ----------
    /**
     * Displays the form for creating a new web authentication configuration.
     *
     * @return HTML response for the web authentication creation form
     */
    @Execute
    @Secured({ ROLE })
    public HtmlResponse createnew() {

{
  "message": "Hello World"
}
```

Of course, you will probably find much better ways to take advantage of this than formatting JSON. 😉

## Default response class { #default-response-class }

When creating a **FastAPI** class instance or an `APIRouter` you can specify which response class to use by default.

The parameter that defines this is `default_response_class`.

    // -----------------------------------------------------
    //                                            Entry Page
    //                                            ----------
    /**
     * Displays the form for creating a new request header item.
     *
     * @return HTML response for the create form
     */
    @Execute
    @Secured({ ROLE })
    public HtmlResponse createnew() {
        saveToken();

      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,

      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,

        // With offset 3 and total 5 items, we should get 2 items
        assertEquals(2, result.size());
        assertEquals(1, result.getCurrentPageNumber()); // First page since we're getting actual results
        assertEquals(10, result.getPageSize());
        assertEquals(5, result.getAllRecordCount());
    }

    public void test_selectList_withNullList() {

                // Implementation for raw payload
            }

            @Override
            public byte[] getRawPayload() {
                // Implementation for getting raw payload
                return null;
            }

            @Override
            public boolean isRetainPayload() {
                // Implementation for retain payload flag

   */
  public static <E> Builder<E> builderWithExpectedSize(int expectedSize) {
    checkNonnegative(expectedSize, "expectedSize");
    return new Builder<>(expectedSize);
  }

  /**
   * A builder for creating {@code ImmutableSet} instances. Example:
   *
   * {@snippet :
   * static final ImmutableSet<Color> GOOGLE_COLORS =
   *     ImmutableSet.<Color>builder()
   *         .addAll(WEBSAFE_COLORS)