public Optional<Long> getLastByteOffsetRead() {
        final long offset = currByteOffset;
        if (offset == -1) {
            return Optional.empty();
        } else {
            return Optional.of(offset);
        }
    }
@param inputStream          The stream to read from. This reader will not close the stream.
@param includeByteOrderMark If true, any BOM in the stream will be included.
@param encoding             The character encoding name of the stream.
stroom-data/stroom-data-store-impl/src/main/java/stroom/data/store/impl/CharReader.java