<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def process_messages_loop_internal(self):
 """ Busy loop that processes incoming WorkRequest messages via functions specified by add_command. Terminates if a command runs shutdown method """

        logging.info("Starting work queue loop.")
        self.connection.receive_loop_with_callback(self.queue_name, self.process_message)