code: def union(self, rdds):
          first_jrdd_deserializer = rdds[0]._jrdd_deserializer
          if any(x._jrdd_deserializer != first_jrdd_deserializer for x in rdds):
              rdds = [x._reserialize() for x in rdds]
          cls = SparkContext._jvm.org.apache.spark.api.java.JavaRDD
          jrdds = SparkContext._gateway.new_array(cls, len(rdds))
          for i in range(0, len(rdds)):
              jrdds[i] = rdds[i]._jrdd
          return RDD(self._jsc.union(jrdds), self, rdds[0]._jrdd_deserializer)