private val _callableNames: Set<Name> by cached {
        val result = mutableSetOf<Name>()
        owner.firSymbol.fir.declarations
            .mapNotNullTo(result) { firDeclaration ->
                when (firDeclaration) {
                    is FirSimpleFunction -> firDeclaration.name
                    is FirProperty -> firDeclaration.name
                    else -> null