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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 list(self, include_claimed=False, echo=False, marker=None, limit=None):
 """ Returns a list of messages for this queue. By default only unclaimed messages are returned; if you want claimed messages included, pass `include_claimed=True`. Also, the requester's own messages are not returned by default; if you want them included, pass `echo=True`. The 'marker' and 'limit' parameters are used to control pagination of results. 'Marker' is the ID of the last message returned, while 'limit' controls the number of messages returned per reuqest (default=20). """

        return self._message_manager.list(include_claimed=include_claimed,
                echo=echo, marker=marker, limit=limit)