@Override
  public void applyLocal(Operation op) {
    TTFOperation oop = (TTFOperation) op;
    int pos = oop.getPosition();

    if (oop.getType() == TraceOperation.OpType.del) {
      TTFChar c = this.model.get(pos);
      c.hide();
    } else {
      this.model.add(pos, new TTFChar(oop.getChar()));
    }
  }