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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 set_acl(self, acl_or_str, key_name='', validate=True, headers=None, version_id=None):
 """sets or updates a bucket's acl"""

        if not self.bucket_name:
            raise InvalidUriError('set_acl on bucket-less URI (%s)' %
                                  self.uri)
        self.get_bucket(validate, headers).set_acl(acl_or_str, key_name,
                                                   headers, version_id)