Changes in explicit constructor invocation aren't detected

[VladyslavBondarenko]

DiffJ v1.6.4 doesn't see a difference between the two classes:

public class MyClass {
    public int a;

    public MyClass(int a) {
        this.a = a;
    }

    public MyClass() {
        this(1);
    }
}

and

public class MyClass {
    public int a;

    public MyClass(int a) {
        this.a = a;
    }

    public MyClass() {
        this(2);
    }
}

The difference is: this(1); => this(2);

This is a real-life case where I experience the issue.