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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_messages(self, num_messages=1, visibility_timeout=None, attributes=None, callback=None):
 """ Get a variable number of messages. :type num_messages: int :param num_messages: The maximum number of messages to read from the queue. :type visibility_timeout: int :param visibility_timeout: The VisibilityTimeout for the messages read. :type attributes: str :param attributes: The name of additional attribute to return with response or All if you want all attributes. The default is to return no additional attributes. Valid values: All SenderId SentTimestamp ApproximateReceiveCount ApproximateFirstReceiveTimestamp :rtype: list :return: A list of :class:`boto.sqs.message.Message` objects. """

        return self.connection.receive_message(self, number_messages=num_messages,
                                               visibility_timeout=visibility_timeout,
                                               attributes=attributes, callback=callback)