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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 instances(self):
 """ Find all of the current instances that are running within this security group. :rtype: list of :class:`boto.ec2.instance.Instance` :return: A list of Instance objects """

        # It would be more efficient to do this with filters now
        # but not all services that implement EC2 API support filters.
        instances = []
        rs = self.connection.get_all_instances()
        for reservation in rs:
            uses_group = [g.name for g in reservation.groups if g.name == self.name]
            if uses_group:
                instances.extend(reservation.instances)
        return instances