*
   * (That would also have ensured that its cause was always an Error, rather than possibly another
   * kind of Throwable that was later passed to initCause. Then we could have declared the override
   * `public final Error getCause()`.)
   */

  /**
   * Creates a new instance with {@code null} as its detail message and no cause.
   *

  }

  @CollectionSize.Require(SEVERAL)
  @MapFeature.Require(SUPPORTS_REMOVE)
  /*
   * SetMultimap.asMap essentially returns a Map<K, Set<V>>; we just can't declare it that way.
   * Thus, calls like asMap().values().remove(someSet) are safe because they are comparing a set to
   * a collection of other sets.
   */
  @SuppressWarnings("CollectionUndefinedEquality")

```console
$ pip install jinja2

---> 100%
```

</div>

## Using `Jinja2Templates` { #using-jinja2templates }

* Import `Jinja2Templates`.
* Create a `templates` object that you can reuse later.
* Declare a `Request` parameter in the *path operation* that will return a template.

# Using Dataclasses { #using-dataclasses }

FastAPI is built on top of **Pydantic**, and I have been showing you how to use Pydantic models to declare requests and responses.

But FastAPI also supports using <a href="https://docs.python.org/3/library/dataclasses.html" class="external-link" target="_blank">`dataclasses`</a> the same way:

{* ../../docs_src/dataclasses/tutorial001.py hl[1,7:12,19:20] *}

     * converter.apply(), anyway. If clients use only converter.convert(), then their nullness
     * checkers are unlikely to ever look at the annotations on this declaration.
     *
     * Historical note: At one point, we'd declared this method as accepting and returning nullable
     * values. For details on that, see earlier revisions of this file.
     */
    return convert(a);
  }

  /**

FROM $BASE_IMAGE AS devel
# See https://docs.docker.com/reference/dockerfile/#understand-how-arg-and-from-interact
# on why we cannot reference BASE_IMAGE again unless we declare it again.
################################################################################

# Install devtoolset build dependencies
COPY setup.sources.sh /setup.sources.sh
COPY setup.packages.sh /setup.packages.sh

 * }
 *
 * <p>Graph algorithms that need additional capabilities (accessing both predecessors and
 * successors, iterating over the edges, etc.) should declare their input to be of a type that
 * provides those capabilities, such as {@link Graph}, {@link ValueGraph}, or {@link Network}.
 *
 * <h3>Additional documentation</h3>
 *

 * }
 *
 * <p>Graph algorithms that need additional capabilities (accessing both predecessors and
 * successors, iterating over the edges, etc.) should declare their input to be of a type that
 * provides those capabilities, such as {@link Graph}, {@link ValueGraph}, or {@link Network}.
 *
 * <h3>Additional documentation</h3>
 *

In this case, the list would have to include `http://localhost:8080` for the `:8080`-frontend to work correctly.

## Wildcards { #wildcards }

It's also possible to declare the list as `"*"` (a "wildcard") to say that all are allowed.

        : new SparseImmutableTable<R, C, V>(cellList, rowSpace, columnSpace);
  }

  /**
   * @throws IllegalArgumentException if {@code existingValue} is not null.
   */
  /*
   * We could have declared this method 'static' but the additional compile-time checks achieved by
   * referencing the type variables seem worthwhile.
   */
  final void checkNoDuplicate(R rowKey, C columnKey, @Nullable V existingValue, V newValue) {