(gnuradio3.8) module 'gnuradio.blocks' has no attribute 'message_sink'

[Ting Wu]

Hi!

I recently upgraded to gnuradio 3.8 and my old code threw the following 
error:

module 'gnuradio.blocks' has no attribute 'message_sink'

Is the 'message_sink' has been deprecated in the recent version of 
gnuradio? If so, what should I use now for the message source and sink? 
I really do not want to rewrite all the codes, so I would be really 
grateful if there is a simple way to make the following code work with 
the recent version of gnuradio. The code simply gets data stream from a 
USRP N200 (LFRX daughterboard).

=================================================
 class my_block(gr.top_block):
    def __init__(self):
        gr.top_block.__init__(self)
        self.source = uhd.usrp_source(device_addr="", 
stream_args=uhd.stream_args('sc16', 'sc16', args="scalar=1024"))

        self.source.set_samp_rate(samp_rate)
        self.source.set_gain(gain)
        self.source.set_center_freq(0)

        self.queue = gr.msg_queue()
        self.sink = blocks.message_sink(gr.sizeof_short*2, self.queue, 
False)  #This line throws the error
        self.connect(self.source, self.sink)
===================================================

Thanks in advance!

Ting Wu