public long getDumpCharCount() {
        final int lineBreakCount = Math.max(0, lines.size() - 1); // No \n on last line
        return lines.stream()
                .mapToInt(HexDumpLine::getDumpLineCharCount) // ignore lack of \n at this point
                .sum()
                + lineBreakCount;
    }
@return The size of the hex dump when output as a string. Not the
number of chars rendered by the hex dump.
stroom-util-shared/src/main/java/stroom/util/shared/string/HexDump.java