public ByteArrayBuilder append(final char chr) {
        try {
            byteArrayOutputStream.write(String.valueOf(chr).getBytes(charset));
        } catch (IOException e) {
            throw new UncheckedIOException(e);
        }
        return this;
    }
@param charset The charset to use for string encoding
stroom-util/src/main/java/stroom/util/string/ByteArrayBuilder.java