code: public static <C extends Compound> String checksum(Sequence<C> sequence) {
  		CRC64Checksum checksum = new CRC64Checksum();
  		for (C compound : sequence) {
  			checksum.update(compound.getShortName());
  		}
  		return checksum.toString();
  	}
docs: Performs a simple CRC64 checksum on any given sequence.