docs: def getBytesForString(self, u):
          """
          Returns the corresponding utf-8 encoded string for a given unicode
          object. If there is no string, one is encoded.
  
          @since: 0.6
          """
          h = hash(u)
          s = self._unicodes.get(h, None)
  
          if s is not None:
              return s
  
          s = self._unicodes[h] = u.encode('utf-8')
  
          return s