}

        return overriddenDescriptors
    }

    override fun isSubClassOf(subClass: KtClassOrObjectSymbol, superClass: KtClassOrObjectSymbol): Boolean {
        if (subClass == superClass) return false

        val subClassDescriptor = getSymbolDescriptor(subClass) as? ClassDescriptor ?: return false
        val superClassDescriptor = getSymbolDescriptor(superClass) as? ClassDescriptor ?: return false

        require(subClass is KtFirSymbol<*>)
        require(superClass is KtFirSymbol<*>)

        if (subClass == superClass) return false
        return isSubClassOf(
            subClass = subClass.firSymbol.fir as FirClass,
            superClass = superClass.firSymbol.fir as FirClass,
            rootModuleSession,

  }

  /**
   * Must be called at the end of each subclass's constructor. This method performs the "real"
   * initialization; we can't put this in the constructor because, in the case where futures are
   * already complete, we would not initialize the subclass before calling {@link
   * #collectValueFromNonCancelledFuture}. As this is called after the subclass is constructed,

 *
 * <p>For details about this hack, see {@code GwtSerializationDependencies}, which takes the same
 * approach but with a subclass rather than a superclass.
 *
 * <p>TODO(cpovirk): Consider applying this subclass approach to our other types.
 */
@SuppressWarnings("rawtypes") // https://github.com/google/guava/issues/989
@GwtCompatible(emulated = true)

        pass

    model = ModelWithCustomEncoder(dt_field=datetime(2019, 1, 1, 8))
    assert jsonable_encoder(model) == {"dt_field": "2019-01-01T08:00:00+00:00"}
    subclass_model = ModelWithCustomEncoderSubclass(dt_field=datetime(2019, 1, 1, 8))
    assert jsonable_encoder(subclass_model) == {"dt_field": "2019-01-01T08:00:00+00:00"}


# TODO: remove when deprecating Pydantic v1
@needs_pydanticv1

* Decompressing gzip-compressed request bodies.
* Automatically logging all request bodies.

## Handling custom request body encodings

Let's see how to make use of a custom `Request` subclass to decompress gzip requests.

And an `APIRoute` subclass to use that custom request class.

### Create a custom `GzipRequest` class

!!! tip

This simple case is handled automatically by FastAPI because the return type annotation is the class (or a subclass) of `Response`.

And tools will also be happy because both `RedirectResponse` and `JSONResponse` are subclasses of `Response`, so the type annotation is correct.

### Annotate a Response Subclass

You can also use a subclass of `Response` in the type annotation:

```Python hl_lines="8-9"

class AbstractFunction : public core::RefCounted {
 protected:
  enum AbstractFunctionKind { kGraph, kMlir };
  explicit AbstractFunction(AbstractFunctionKind kind) : kind_(kind) {}

 public:
  // Returns which subclass is this instance of.
  AbstractFunctionKind getKind() const { return kind_; }

  // Returns the AbstractFunction as a FunctionDef.
  virtual Status GetFunctionDef(const FunctionDef**) = 0;

/**
 * A utility similar to {@link IteratorTester} for testing a {@link ListIterator} against a known
 * good reference implementation. As with {@code IteratorTester}, a concrete subclass must provide
 * target iterators on demand. It also requires three additional constructor parameters: {@code
 * elementsToInsert}, the elements to be passed to {@code set()} and {@code add()} calls; {@code

/**
 * A utility similar to {@link IteratorTester} for testing a {@link ListIterator} against a known
 * good reference implementation. As with {@code IteratorTester}, a concrete subclass must provide
 * target iterators on demand. It also requires three additional constructor parameters: {@code
 * elementsToInsert}, the elements to be passed to {@code set()} and {@code add()} calls; {@code