code: def send_capture_messages(self):
      for msg in self.capture_messages:
          self.port.callback(msg)
  
imports: import collections
  import queue
  import threading
  import time
  from magenta.common import concurrency
  from magenta.interfaces.midi import midi_hub
  import mido
  from note_seq import testing_lib
  from note_seq.protobuf import music_pb2
  import tensorflow.compat.v1
label_desc: Use image node_id 3 for calling the MidiHubTest obj's underlying member method code with example usage: obj.send_capture_messages() without return types