code: protected String readFile(File file, List<String> lines) {
      int		i;
  
      try {
        lines.addAll(Files.readAllLines(file.toPath()));
        i = 0;
        while (i < lines.size()) {
          if (lines.get(i).trim().isEmpty()) {
            lines.remove(i);
            continue;
  	}
  	if (lines.get(i).startsWith("#")) {
            lines.remove(i);
            continue;
  	}
  	i++;
        }
      }
      catch (Exception e) {
        return "Failed to read file: " + file + "\n" + e;
      }
  
      return null;
    }
docs: Reads the file into the the provided list.
  Skips empty lines and lines starting with #.
  
  @param file	the file to read
  @param lines 	the lines to add the content to
  @return 		null if successful, otherwise error message