How to programatically determine if a function is isolated or not in Ballerina?

In my Ballerina code, I need to validate whether a given Ballerina function is isolated within my logic. What would be the recommended way to do that?

isolated is part of the type. you can check for is isolated function as follows.

import ballerina/io;

public function f1() returns int => 1;
public isolated function f2() returns int => 1;

public function main() {
    boolean isolatedFn = f1 is isolated function () returns int;
    io:println(isolatedFn);

    // should be possible, but not allowed atm, param/return types have to match
    io:println(f1 is isolated function);

    function f = f1;
    io:println(f is isolated function);
    io:println(<function> f2 is isolated function);
}

Please note that this check will be true for functions that are inferred as isolated(https://ballerina.io/learn/by-example/inferring-isolated/) as well.