public int getSourceLineNumber(int _start, boolean _exact) {
            final Iterator<StartLineNumberPair> i = getPool().iterator();
            if (i.hasNext()) {
               StartLineNumberPair from = i.next();
               while (i.hasNext()) {
                  final StartLineNumberPair to = i.next();
                  if (_exact) {
                     if (_start == from.getStart()) {
                        return (from.getLineNumber());
                     }
                  } else if ((_start >= from.getStart()) && (_start < to.getStart())) {
                     return (from.getLineNumber());
                  }
                  from = to;
               }
               if (_exact) {
                  if (_start == from.getStart()) {
                     return (from.getLineNumber());
                  }
               } else if (_start >= from.getStart()) {
                  return (from.getLineNumber());
               }
            }

            return (-1);
         }