<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_all_queues(self, prefix=''):
 """ Retrieves all queues. :keyword str prefix: Optionally, only return queues that start with this value. :rtype: list :returns: A list of :py:class:`boto.sqs.queue.Queue` instances. """

        params = {}
        if prefix:
            params['QueueNamePrefix'] = prefix
        return self.get_list('ListQueues', params, [('QueueUrl', Queue)])