code: @Override
    public int compareTo(DistanceEntry<E> o) {
      int comp = Double.compare(distance, o.distance);
      return comp;
      // return comp != 0 ? comp :
      // entry.getEntryID().compareTo(o.entry.getEntryID());
    }
docs: Compares this object with the specified object for order.
  
  @param o the Object to be compared.
  @return a negative integer, zero, or a positive integer as this object is
  less than, equal to, or greater than the specified object.
  @throws ClassCastException if the specified object's type prevents it from
  being compared to this Object.