@Override
 public Object clone() throws CloneNotSupportedException {
   try {
     return super.clone();
   } catch (CloneNotSupportedException e) {
     throw new InternalError(e.getMessage());
   }
 }
 public Liner clone() {
   try {
     return (Liner) super.clone();
   } catch (CloneNotSupportedException ex) {
     InternalError error = new InternalError(ex.getMessage());
     error.initCause(ex);
     throw error;
   }
 }