code: def window(self, windowDuration, slideDuration=None):
          
          self._validate_window_param(windowDuration, slideDuration)
          d = self._ssc._jduration(windowDuration)
          if slideDuration is None:
              return DStream(self._jdstream.window(d), self._ssc, self._jrdd_deserializer)
          s = self._ssc._jduration(slideDuration)
          return DStream(self._jdstream.window(d, s), self._ssc, self._jrdd_deserializer)
docs: Return a new DStream in which each RDD contains all the elements in seen in a
          sliding window of time over this DStream.
  
          @param windowDuration: width of the window; must be a multiple of this DStream's
                                batching interval
          @param slideDuration:  sliding interval of the window (i.e., the interval after which
                                the new DStream will generate RDDs); must be a multiple of this
                                DStream's batching interval