@Override
    public ApplicationFile delete() {
        if (!listFiles().isEmpty()) {
            throw new RuntimeException("Can't delete, directory not empty: " + this);
        }
        zkApp.deleteRecurse(getZKPath(path));
        writeMetaFile(ContentStatusDeleted);
        return this;
    }
@author Ulf Lilleengen
@author Vegard Havdal
configserver/src/main/java/com/yahoo/vespa/config/server/zookeeper/ZKApplicationFile.java