docs: @SuppressWarnings("unchecked")
    @Ensures({
      "lines == null ? result == null : isLineNumberList(result)"
    })
    static List<Long> getLineNumbers(Object lines) {
      if (lines == null) {
        return null;
      }
  
      ArrayList<Long> lineNumbers = new ArrayList<Long>();
      if (lines.getClass().isArray()) {
        for (long line : (long[]) lines) {
          lineNumbers.add(line < 1 ? null : line);
        }
      } else {
        for (Long line : (List<Long>) lines) {
          lineNumbers.add(line < 1 ? null : line);
        }
      }
  
      return lineNumbers;
    }