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"

        }

        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

) : KtSubstitutorProvider(), KtFirAnalysisSessionComponent {
    override fun createSubstitutor(
        subClass: KtClassOrObjectSymbol,
        superClass: KtClassOrObjectSymbol,
    ): KtSubstitutor? {
        if (subClass == superClass) return KtSubstitutor.Empty(token)

        val baseFirSymbol = subClass.firSymbol
        val superFirSymbol = superClass.firSymbol

 * The performance of these calls on the underlying network. If the network’s performance isn’t sufficient, you need to either improve the network or use less of it.

### EventListener

    override val element: KtThisExpression,
) : ElementToShorten() {
    override val nameToImport: FqName? = null
    override val importAllInParent: Boolean = false
}

/**
 * N.B. Does not subclass [ElementToShorten] because currently
 * there's no reason to do that.
 */
private class ShortenKDocQualifier(
    val element: KDocName,
)

             * no separate symbol for that case.
             *
             * Java statics present a similar case - they can be imported not only from the declaring class,
             * but also from any subclass.
             */
            private fun FirQualifiedAccessExpression.importableNameForImplicitlyDispatchedCallable(): FqName? {
                val dispatchReceiver = dispatchReceiver
                if (

avoids/fixes a potential security issue: as the returned object is passed directly to Pydantic, if the returned object was a subclass of the `response_model` (e.g. you return a `UserInDB` that inherits from `User` but contains extra fields, like `hashed_password`, and `User` is used in the `response_model`), it would still pass the validation (because `UserInDB` is a subclass of `User`) and the object would be returned as-is, including the `hashed_password`. To fix this, the declared `response_model`...