public int add(BTDownloadDataLine tl,int row){
  if (!allow(tl)) {
    HIDDEN.add(tl);
    return -1;
  }
 else {
    return super.add(tl,row);
  }
}

public int add ( BTDownloadDataLine tl , int row ) { if ( ! allow ( tl ) ) { HIDDEN . add ( tl ) ; return - 1 ; } else { return super . add ( tl , row ) ; } }
determines whether or not this line should be added .
