@Override
    public int read(@NotNull final byte[] b, final int off, final int len) throws IOException {
        if (streamAdaptor == null) {
            // LAZY
            return -1;
        } else {
            int read = streamAdaptor.read(b, off, len);
            if (read != -1) {
                position += read;
            }
            return read;
        }
    }
@param b   to fill
@param off offset
@param len length
stroom-data/stroom-data-store-impl-fs/src/main/java/stroom/data/store/impl/fs/UncompressedInputStream.java