code: def byte_offset(self, bytes):
          
          remaining_bytes = bytes
          for r in self:
              if r.is_open() or r.byte_length() >= remaining_bytes:
                  return r.start + remaining_bytes
              else:
                  remaining_bytes -= r.byte_length()
          assert False, "requested byte offset {0!r} is outside the range list {1!r}".format(bytes, self)
docs: Maps `bytes` length to a sequence's offset. For example, if we do byte_offset(5) and our list of sequences is
          [(0, 2), (10, 11), (40, 45)] then the returned value will be 42.
          Note that `bytes` must be <= byte_length().
          :returns: actual offset in one of the sequences in the range for request byte length.
          :rtype: int or float