private Count<Long> estimateCharCount(final long totalBytes, final Charset charset) {
        return Count.approximately((long) Math.floor(
                charset.newDecoder().averageCharsPerByte() * totalBytes));
    }
How big our buffers are. This should always be a multiple of 8.
stroom-data/stroom-data-store-impl/src/main/java/stroom/data/store/impl/DataFetcher.java