@Operation(summary = "list", description = "List clusters")
    @GetMapping
    public ResponseEntity<List<ClusterVO>> list() {
        return ResponseEntity.success(clusterService.list());
    }
@Test
    void listReturnsAllClusters() {
        List<ClusterVO> clusters = Arrays.asList(new ClusterVO(), new ClusterVO());
        when(clusterService.list()).thenReturn(clusters);

        ResponseEntity<List<ClusterVO>> response = clusterController.list();

        assertTrue(response.isSuccess());
        assertEquals(clusters, response.getData());
    }