code: public boolean set(long index) {
      if (!(index < size))
        throw new IndexOutOfBoundsException();
      if (!get(index)) {
        bytes.writeLong(offset(index), bytes.readLong(offset(index)) | (1l << position(index)));
        count++;
        return true;
      }
      return false;
    }
docs: Sets the bit at the given index.
  
  @param index The index of the bit to set.
  @return Indicates if the bit was changed.