throws IOException {
if (DEBUG) LOG.debug("init from page at offset "+ offset + " for length " + (page.length - offset));
this.in = new ByteArrayInputStream(page, offset, page.length - offset);
int bitWidth = BytesUtils.readIntLittleEndianOnOneByte(in);
if (DEBUG) LOG.debug("bit width " + bitWidth);
decoder = new RunLengthBitPackingHybridDecoder(bitWidth, in);
}