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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 rbac_policy_update(request, policy_id, **kwargs):
 """Update a RBAC Policy. :param request: request context :param policy_id: target policy id :param target_tenant: target tenant of the policy :return: RBACPolicy object """

    body = {'rbac_policy': kwargs}
    rbac_policy = neutronclient(request).update_rbac_policy(
        policy_id, body=body).get('rbac_policy')
    return RBACPolicy(rbac_policy)