code: public void align() throws IOException {
  		if (capacity < BITS_IN_BYTE) {
  			ostream.write(buffer << capacity);
  			capacity = BITS_IN_BYTE;
  			buffer = 0;
  			len++;
  		}
  	}
docs: If there are some unwritten bits, pad them if necessary and write them
  out.
  
  @throws IOException
  IO exception