Parses a pub/sub message. If the channel or pattern was subscribed to
        with a message handler, the handler is invoked instead of a parsed
        message being returned.

def handle_message(self, response, ignore_subscribe_messages=False):
        """
        Parses a pub/sub message. If the channel or pattern was subscribed to
        with a message handler, the handler is invoked instead of a parsed
        message being returned.
        """
        message_type = nativestr(response[0])
        if message_type == 'pmessage':
            message = {
                'type': message_type,
                'pattern': response[1],
                'channel': response[2],
                'data': response[3]
            }
        elif message_type == 'pong':
            message = {
                'type': message_type,
                'pattern': None,
                'channel': None,
                'data': response[1]
            }
        else:
            message = {
                'type': message_type,
                'pattern': None,
                'channel': response[1],
                'data': response[2]
            }

        # if this is an unsubscribe message, remove it from memory
        if message_type in self.UNSUBSCRIBE_MESSAGE_TYPES:
            if message_type == 'punsubscribe':
                pattern = response[1]
                if pattern in self.pending_unsubscribe_patterns:
                    self.pending_unsubscribe_patterns.remove(pattern)
                    self.patterns.pop(pattern, None)
            else:
                channel = response[1]
                if channel in self.pending_unsubscribe_channels:
                    self.pending_unsubscribe_channels.remove(channel)
                    self.channels.pop(channel, None)

        if message_type in self.PUBLISH_MESSAGE_TYPES:
            # if there's a message handler, invoke it
            if message_type == 'pmessage':
                handler = self.patterns.get(message['pattern'], None)
            else:
                handler = self.channels.get(message['channel'], None)
            if handler:
                handler(message)
                return None
        elif message_type != 'pong':
            # this is a subscribe/unsubscribe message. ignore if we don't
            # want them
            if ignore_subscribe_messages or self.ignore_subscribe_messages:
                return None

        return message