compareTo with two fields

Human.java

public int compareTo(Human other) {
  if(age < other.age) {
    return -1;
  } else if (age > other.age) {
    return 1;
  } else {
    // Fall back to the logic for the second field only if the first two are equal.
    if(guiltyPleasure < other.guiltyPleasure) {
      return -1;
    } else if(guiltyPleasure > other.guiltyPleasure) {
      return 1;
    } else {
      return 0;
    }
  }
}