code: def _posix_split_name(self, name):
          
          prefix = name[:LENGTH_PREFIX + 1]
          while prefix and prefix[-1] != "/":
              prefix = prefix[:-1]
  
          name = name[len(prefix):]
          prefix = prefix[:-1]
  
          if not prefix or len(name) > LENGTH_NAME:
              raise ValueError("name is too long")
          return prefix, name
docs: Split a name longer than 100 chars into a prefix
             and a name part.