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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 update(self, validate=False):
 """ Update the instance's state information by making a call to fetch the current instance attributes from the service. :type validate: bool :param validate: By default, if EC2 returns no data about the instance the update method returns quietly. If the validate param is True, however, it will raise a ValueError exception if no data is returned from EC2. """

        rs = self.connection.get_all_instances([self.id])
        if len(rs) > 0:
            r = rs[0]
            for i in r.instances:
                if i.id == self.id:
                    self._update(i)
        elif validate:
            raise ValueError('%s is not a valid Instance ID' % self.id)
        return self.state