private StagingValue convert(final RefDataValue refDataValue) {
        return StagingValueSerde.convert(ByteBuffer::allocateDirect, xxHashAlgorithm, refDataValue);
    }
Generate a list (of size desiredRecords) of strings that all share the same hashcode
Adapted from https://gist.github.com/vaskoz/5703423
stroom-pipeline/src/test/java/stroom/pipeline/refdata/store/offheapstore/databases/TestValueStoreDb.java