Read a single message from the queue.
        
        :type visibility_timeout: int
        :param visibility_timeout: The timeout for this message in seconds

        :rtype: :class:`boto.sqs.message.Message`
        :return: A single message or None if queue is empty

def read(self, visibility_timeout=None):
        """
        Read a single message from the queue.
        
        :type visibility_timeout: int
        :param visibility_timeout: The timeout for this message in seconds

        :rtype: :class:`boto.sqs.message.Message`
        :return: A single message or None if queue is empty
        """
        rs = self.get_messages(1, visibility_timeout)
        if len(rs) == 1:
            return rs[0]
        else:
            return None