How to detect ambiguous method calls that would cause a ClassCastException in Java 8?

Question

We are currently in the process of migrating an application from Java 7 to Java 8. After fixing a some compilation issues, I stumbled upon an issue similar to the following ques

Answer 1

A better alternative would be:

public class Test {
    public static void main(String[] args) {
        System.out.println(String.valueOf(getVal("xxx"))); // 7: prints the result, 8: Exception
    }

    @SuppressWarnings("unchecked")
    public static  T getVal(T param) {
        // do some computation based on param...
        return   param; // actual return type only depends on param so the caller knows what to expect
    }
}

which will work in both Java 7 and Java 8.