code: private void addLineNumber(BitSet lineNumbers) {
          LineNumberTable lnt = getCode().getLineNumberTable();
          if (lnt == null) {
              lineNumbers.set(0);
          } else {
              int line = lnt.getSourceLine(getPC());
              if (line < 0) {
                  lineNumbers.set(lineNumbers.size());
              } else {
                  lineNumbers.set(line);
              }
          }
      }
docs: add the current line number to a set of line numbers
  
  @param lineNumbers
  the current set of line numbers