public static String getXxhash64(ByteBuffer input) {
        XXHash64 hasher = XXHashFactory.fastestInstance().hash64();
        return Long.toHexString(hasher.hash(input, 0)).toLowerCase();
    }
Utilities for mangling config text, finding checksums, finding name and namespace in .def files etc.
config/src/main/java/com/yahoo/vespa/config/util/ConfigUtils.java