'Replaces the current set of policies associated with a port on which
the back-end server is listening with a new set of policies.'

def set_lb_policies_of_backend_server(self, lb_name, instance_port, policies):

    params = {'LoadBalancerName': lb_name, 'InstancePort': instance_port}
    if policies:
        self.build_list_params(params, policies, 'PolicyNames.member.%d')
    else:
        params['PolicyNames'] = ''
    return self.get_status('SetLoadBalancerPoliciesForBackendServer', params)
