docs: def __folder_size(self, path):
          """Return the size of the directory given by path
  
          path: <string>"""
  
          ret = 0
          for f in scandir(path):
              if f.is_dir() and (f.name != '.' or f.name != '..'):
                  ret += self.__folder_size(os.path.join(path, f.name))
              else:
                  try:
                      ret += f.stat().st_size
                  except OSError:
                      pass
  
          return ret