private val metadataVersion = firSession.languageVersionSettings.languageVersion.toMetadataVersion()

    override fun calculateMetadata(ktClass: KtClassOrObject, mapping: Multimap<KtElement, PsiElement>): Metadata {
        val firClass = ktClass.resolveToFirSymbolOfType<FirClassSymbol<*>>(firResolveSession).fir
        firClass.lazyResolveToPhaseWithCallableMembers(FirResolvePhase.STATUS)

            is KtPrimaryConstructor ->
                false // error?
            // no children of secondary constructs are used.
            is KtSecondaryConstructor ->
                false

            // KtClass, KtObjectDeclaration, KtTypeAlias has no expression children
            is KtClassLikeDeclaration ->
                false // has no expression children

            // Simple names do not have expression children