override val symbol: S
        get() = withValidityAssertion { firSymbol.buildSymbol(firSymbolBuilder) as S }
    override val returnType: KtType by cached {
        firSymbolBuilder.typeBuilder.buildKtType(coneSubstitutor.substituteOrSelf(firSymbol.resolvedReturnType))
    }
    override val receiverType: KtType? by cached {
        val receiverTypeRef = when (val fir = firSymbol.fir) {