public static Coordinate ptNotInList(Coordinate[] testPts,Coordinate[] pts){
  for (int i=0; i < testPts.length; i++) {
    Coordinate testPt=testPts[i];
    if (!isInList(testPt,pts))     return testPt;
  }
  return null;
}

public static Coordinate ptNotInList ( Coordinate [ ] testPts , Coordinate [ ] pts ) { for ( int i = 0 ; i < testPts . length ; i ++ ) { Coordinate testPt = testPts [ i ] ; if ( ! isInList ( testPt , pts ) ) return testPt ; } return null ; }
finds a point in a list of points which is not contained in another list of points
