code: private int bitsAtVersion( int version ) {
  		int total = 0;
  		for (int i = 0; i < segments.size(); i++) {
  			total += segments.get(i).sizeInBits(version);
  		}
  		return total;
  	}
docs: Computes how many bits it takes to encode the message at this version number
  @param version
  @return