docs: public String createSubdir() throws IOException {
  
          if (!saveData)
              return "";
  
          File dr = new File(dataRoot);
          dr.mkdirs();
          File[] rootChildren = dr.listFiles();
  
          int i = 1;
          while (childrenExist(rootChildren, i + ""))
              i++;
  
          File f = new File(dataRoot + "/" + i);
          f.mkdirs();
  
          currentDir = f.getAbsolutePath();
          log.info("Created training data directory: " + currentDir);
  
          File mov = new File(getVideoDir());
          mov.mkdirs();
  
          File model = new File(getModelDir());
          model.mkdirs();
  
          File stat = new File(getStat());
          File info = new File(getInfo());
          stat.createNewFile();
          info.createNewFile();
          return f.getAbsolutePath();
      }