code: public void deserialize(DataInput in) throws IOException {
      try {
        getMappeableRoaringArray().deserialize(in);
      } catch(InvalidRoaringFormat cookie) {
        throw cookie.toIOException();// we convert it to an IOException
      }
    }
docs: Deserialize the bitmap (retrieve from the input stream). The current bitmap is overwritten.
  
  See format specification at https://github.com/RoaringBitmap/RoaringFormatSpec
  
  @param in the DataInput stream
  @throws IOException Signals that an I/O exception has occurred.