'Replaces the current set of policies associated with a port on
which the back-end server is listening with a new set of policies
:param name: balancer name to set policies of backend server
:type  name: ``str``
:param instance_port: Instance Port
:type  instance_port: ``int``
:param policies: List of policies to be associated with the balancer
:type  policies: ``string list`'

def ex_set_balancer_policies_backend_server(self, name, instance_port, policies):

    params = {'Action': 'SetLoadBalancerPoliciesForBackendServer', 'LoadBalancerName': name, 'InstancePort': str(instance_port)}
    if policies:
        params = self._create_list_params(params, policies, 'PolicyNames.member.%d')
    response = self.connection.request(ROOT, params=params)
    return (response.status == httplib.OK)
