How to use the comiccrawler.channel.mission_ch.pub function in comiccrawler

print("page {} already exist".format(crawler.ep.total + 1))
			crawler.next_image()
			return
			
		debug_log("D_RESOLVE")
		crawler.resolve_image()
		print("Downloading {} page {}: {}\n".format(
			crawler.ep.title, crawler.ep.total + 1, crawler.image.url))
		debug_log("D_DOWNLOAD")
		crawler.download_image()
		debug_log("D_HANDLE")
		crawler.handle_image()
		debug_log("D_SAVE")
		crawler.save_image()
		debug_log("D_PUB")
		mission_ch.pub("MISSION_PROPERTY_CHANGED", crawler.mission)
		debug_log("D_REST")
		crawler.rest()
		debug_log("D_NEXT_IMAGE")
		crawler.next_image()

print("page {} already exist".format(crawler.ep.total + 1))
			crawler.next_image()
			return
			
		debug_log("D_RESOLVE")
		crawler.resolve_image()
		print("Downloading {} page {}: {}\n".format(
			crawler.ep.title, crawler.ep.total + 1, crawler.image.url))
		debug_log("D_DOWNLOAD")
		crawler.download_image()
		debug_log("D_HANDLE")
		crawler.handle_image()
		debug_log("D_SAVE")
		crawler.save_image()
		debug_log("D_PUB")
		mission_ch.pub("MISSION_PROPERTY_CHANGED", crawler.mission)
		debug_log("D_REST")
		crawler.rest()
		debug_log("D_NEXT_IMAGE")
		crawler.next_image()

ep_data["total"] += 1
							
					episodes.append(Episode(**ep_data))
				m_data["episodes"] = episodes
			mission = create_mission(**m_data)
			
			self.pool[mission.url] = mission

		for url in view:
			self.view[url] = self.pool[url]

		for url in library:
			self.library[url] = self.pool[url]

		mission_ch.pub("MISSION_LIST_REARRANGED", self.view)
		mission_ch.pub("MISSION_LIST_REARRANGED", self.library)

def __setattr__(self, name, value):
		with mission_lock:
			setattr(self.mission, name, value)
		mission_ch.pub("MISSION_PROPERTY_CHANGED", self)

def __setattr__(self, name, value):
		with mission_lock:
			setattr(self.mission, name, value)
		mission_ch.pub("MISSION_PROPERTY_CHANGED", self)

def drop(self, pool_name, *missions):
		"""Drop missions to the bottom."""
		pool = getattr(self, pool_name)
		with self.lock:
			for mission in missions:
				pool.move_to_end(mission.url)
		mission_ch.pub("MISSION_LIST_REARRANGED", pool)
		self.edit = True