class DuplicateRemover {

  public static void main(String[] args) throws IOException {<FILL_FUNCTION_BODY>}
}

    if (args.length != 1) {
      System.out.println("Usage: " + DuplicateRemover.class.getSimpleName() + " <file>");
      System.exit(1);
    }
    List<String> lines = Files.readAllLines(Paths.get(args[0]));
    Set<String> seenBefore = new HashSet<>();
    for (String line : lines) {
      line = line.trim();
      if (line.startsWith("#")) {
        System.out.println(line);
      } else if (seenBefore.contains(line)) {
        //System.err.println("Ignoring " + line);
      } else {
        System.out.println(line);
      }
      seenBefore.add(line);
    }
  
<no_super_class>