code: def main(unused_argv):
      tf.logging.set_verbosity(FLAGS.log)
  
      # Initialize MidiHub.
      hub = midi_hub.MidiHub(
          None,
          FLAGS.output_ports.split(","),
          midi_hub.TextureType.MONOPHONIC,
      )
  
      cc = FLAGS.clock_control_number
  
      # Assumes 4 beats per bar.
      metronome_signals = [
          midi_hub.MidiSignal(control=cc, value=127)
      ] + [midi_hub.MidiSignal(control=cc, value=0)] * 3
  
      hub.start_metronome(
          FLAGS.qpm,
          start_time=0,
          signals=metronome_signals,
          channel=FLAGS.channel,
      )
  
      try:
          while True:
              time.sleep(1)
      except KeyboardInterrupt:
          hub.stop_metronome()
  
      print("Clock stopped.")
  
imports: import time
  from magenta.interfaces.midi import midi_hub
  import tensorflow.compat.v1
label_desc: Use image node_id 1 for calling a global function with example usage: main(unused_argv) without return types