private String nodeName(String baseName, CreateMode createMode) {
        return switch (createMode) {
            case PERSISTENT, EPHEMERAL, PERSISTENT_WITH_TTL -> baseName;
            case PERSISTENT_SEQUENTIAL, EPHEMERAL_SEQUENTIAL -> baseName + monotonicallyIncreasingNumber++;
            default -> throw new UnsupportedOperationException(createMode + " support not implemented in MockCurator");
        };
    }
Returns a node or throws the appropriate exception if it doesn't exist
zkfacade/src/main/java/com/yahoo/vespa/curator/mock/MockCuratorFramework.java