in src/core/Element.hack [47:55]
final protected async function __flushSubtree(): Awaitable<primitive> {
try {
$that = await $this->__flushRenderedRootElement();
return await $that->__flushSubtree();
} catch (UseAfterRenderException $e) {
$e->__viaXHPPath(static::class);
throw $e;
}
}