question: @ Override public int compareTo ( Object o ) { Outlier outlier = ( Outlier ) o ; Point2D p1 = getPoint ( ) ; Point2D p2 = outlier . getPoint ( ) ; if ( p1 . equals ( p2 ) ) { return 0 ; } else if ( ( p1 . getX ( ) < p2 . getX ( ) ) || ( p1 . getY ( ) < p2 . getY ( ) ) ) { return - 1 ; } else { return 1 ; } }
target:  Compares this object with the specified object for order, based on the outlier's point.