module BinData::IO::Read::UnSeekableStream

def seek_raw(n)
  raise IOError, "stream is unseekable" if n < 0
  # skip over data in 8k blocks
  while n > 0
    bytes_to_read = [n, 8192].min
    read_raw(bytes_to_read)
    n -= bytes_to_read
  end
end