### Question:
RestBackendImpl implements RestBackend { @Override public Set<String> getClusters(String domainUid) { LOGGER.entering(domainUid); verifyDomain(domainUid); authorize(domainUid, Operation.get); Map<String, WlsClusterConfig> wlsClusterConfigs = getWlsConfiguredClusters(domainUid); Set<String> result = wlsClusterConfigs.keySet(); LOGGER.exiting(result); return result; } RestBackendImpl(String principal, String accessToken, Collection<String> targetNamespaces); @Override Set<String> getDomainUids(); @Override boolean isDomainUid(String domainUid); @Override void performDomainAction(String domainUid, DomainAction params); @Override Set<String> getClusters(String domainUid); @Override boolean isCluster(String domainUid, String cluster); @Override void scaleCluster(String domainUid, String cluster, int managedServerCount); static final String INITIAL_VERSION; }### Answer:
@Test public void retrieveDefinedClusters() { configSupport.addWlsCluster("cluster1", "ms1", "ms2", "ms3"); configSupport.addWlsCluster("cluster2", "ms4", "ms5", "ms6"); setupScanCache(); assertThat(restBackend.getClusters(NAME1), containsInAnyOrder("cluster1", "cluster2")); }