public boolean isInMaintenance(ApplicationInstance appInstance, HostName hostName) {
        try {
            ClusterId clusterName = VespaModelUtil.getContentClusterName(appInstance, hostName);
            int storageNodeIndex = VespaModelUtil.getStorageNodeIndex(appInstance, hostName);
            String globalMapKey = clusterName + "/" + ContentService.STORAGE_NODE.nameInClusterController() + "/" + storageNodeIndex;
            return nodes.getOrDefault(globalMapKey, ClusterControllerNodeState.UP) == ClusterControllerNodeState.MAINTENANCE;
        } catch (Exception e) {
            //Catch all - meant to catch cases where the node is not part of a storage cluster
            return false;
        }
    }
Mock implementation of ClusterControllerClient
<p>

@author smorgrav
orchestrator/src/test/java/com/yahoo/vespa/orchestrator/controller/ClusterControllerClientFactoryMock.java