code: def slice(self, begin, end):
          
          return self.transform(lambda time_, rdd:
                                rdd if begin <= time_ <= end
                                else EmptyRDD(self._context._context))
docs: Filter RDDs to between begin and end.
  
          :param datetime.datetime|int begin: datetiem or unix timestamp
          :param datetime.datetime|int end: datetiem or unix timestamp
          :rtype: DStream