### Question:
SDNCServiceInstanceResources { public GenericResourceApiServiceOperationInformation changeModelServiceInstance(ServiceInstance serviceInstance, Customer customer, RequestContext requestContext) { return sdncRM.reqMapper(SDNCSvcOperation.SERVICE_TOPOLOGY_OPERATION, SDNCSvcAction.CHANGE_ASSIGN, GenericResourceApiRequestActionEnumeration.CREATESERVICEINSTANCE, serviceInstance, customer, requestContext); }  GenericResourceApiServiceOperationInformation assignServiceInstance(ServiceInstance serviceInstance,
            Customer customer, RequestContext requestContext); GenericResourceApiServiceOperationInformation deleteServiceInstance(ServiceInstance serviceInstance,
            Customer customer, RequestContext requestContext); GenericResourceApiServiceOperationInformation unassignServiceInstance(ServiceInstance serviceInstance,
            Customer customer, RequestContext requestContext); GenericResourceApiServiceOperationInformation deactivateServiceInstance(ServiceInstance serviceInstance,
            Customer customer, RequestContext requestContext); GenericResourceApiServiceOperationInformation changeModelServiceInstance(ServiceInstance serviceInstance,
            Customer customer, RequestContext requestContext);  }### Answer:
@Test public void test_changeModelServiceInstance() throws MapperException, BadResponseException { doReturn(new GenericResourceApiServiceOperationInformation()).when(MOCK_serviceTopologyOperationMapper) .reqMapper(eq(SDNCSvcOperation.SERVICE_TOPOLOGY_OPERATION), eq(SDNCSvcAction.CHANGE_ASSIGN), eq(GenericResourceApiRequestActionEnumeration.CREATESERVICEINSTANCE), any(ServiceInstance.class), any(Customer.class), any(RequestContext.class)); sdncServiceInstanceResources.changeModelServiceInstance(serviceInstance, customer, requestContext); verify(MOCK_serviceTopologyOperationMapper, times(1)).reqMapper(eq(SDNCSvcOperation.SERVICE_TOPOLOGY_OPERATION), eq(SDNCSvcAction.CHANGE_ASSIGN), eq(GenericResourceApiRequestActionEnumeration.CREATESERVICEINSTANCE), any(ServiceInstance.class), any(Customer.class), any(RequestContext.class)); }