Look for qualified this usages in the same class.
Examples:
public class ToStringDemo extends Super{ private String secondName; @Override public String toString() { return super.toString() + "ToStringDemo{" + "secondName='" + secondName + '\'' + '}'; } } class Super { private String firstName; @Override public String toString() { return "Super{" + "firstName=" + firstName + '\'' + '}'; } }