*/
private val FirFunctionCall.functionReferenceName: Name?
    get() {
        toResolvedCallableReference()?.let { return it.name }

        // unresolved reference has incorrect name, so we have to retrieve it by PSI
        val wholeCallExpression = realPsi as? KtExpression
        val callExpression = wholeCallExpression?.getPossiblyQualifiedCallExpression()