@Override
    public Set<String> get(URL url) {
        String serviceInterface = url.getServiceInterface();
        String registryCluster = getRegistryCluster(url);
        MetadataReport metadataReport = metadataReportInstance.getMetadataReport(registryCluster);
        if (metadataReport == null) {
            return Collections.emptySet();
        }
        return metadataReport.getServiceAppMapping(serviceInterface, url);
    }
@Test
    void testGet() {
        Set<String> set = new HashSet<>();
        set.add("app1");

        MetadataReportInstance reportInstance = mock(MetadataReportInstance.class);
        Mockito.when(reportInstance.getMetadataReport(any())).thenReturn(metadataReport);
        when(metadataReport.getServiceAppMapping(any(), any())).thenReturn(set);

        mapping.metadataReportInstance = reportInstance;
        Set<String> result = mapping.get(url);
        assertEquals(set, result);
    }