def reserialize(new_serializer)
      if serializer == new_serializer
        return self
      end

      new_command = @command.deep_copy
      new_command.serializer = new_serializer

      PipelinedRDD.new(self, new_command)
    end
def reserialize(new_serializer)
      if serializer == new_serializer
        return self
      end

      new_command = @command.deep_copy
      new_command.serializer = new_serializer

      PipelinedRDD.new(self, new_command)
    end
Return a new RDD with different serializer. This method is useful during union
 and join operations.

 == Example:
   rdd = $sc.parallelize([1, 2, 3], nil, serializer: "marshal")
   rdd = rdd.map(lambda{|x| x.to_s})
   rdd.reserialize("oj").collect
   # => ["1", "2", "3"]