Lets say you have some input json that you want to slightly modify to something else. How would you do this with unknown? I can't just blindly replace any with unknown. I'd get errors like this: The right-hand side of a 'for...in' statement must be of type 'any', an object type or a type parameter, but here has type 'unknown'.ts(2407) For example, how can I do this better?

Remember the input json could be pretty much anything. I don't have a spec other than I only care about things that end with __c.

https://github.com/kusl/salesforcecontactmapper/blob/eff0b3e...

    import { Output } from "./Output";
    import { Preference } from "./Preference";

    export function MyMap(input: unknown): Output {
        const mypreferences = Array<Preference>();
        for (const prefCode in input) {
            if (prefCode.endsWith("__c")) {
                if (prefCode === "IsInternalUpdate__c") {
                    continue;
                }
                let currentValue = "";
                if (input[prefCode] !== null) {
                    currentValue = input[prefCode].toString();
                }
                if (currentValue === "true") {
                    currentValue = "True";
                }
                if (currentValue === "false") {
                    currentValue = "False";
                }
                const preference: Preference = {
                    PrefCode: prefCode,
                    CurrentValue: currentValue
                }
                mypreferences.push(preference);
            }
        }
        const myOutput: Output = {
            ContactId: input.Contact__c,
            Email: input.ContactEmail__c,
            IsInternalUpdate: true,
            Preferences: mypreferences
        }
        return myOutput;
    }