code: public static int compareVersions(String v1, String v2) {
  		String s1 = normalisedVersion(v1);
  		String s2 = normalisedVersion(v2);
  		return s1 != null ? (s2 != null ? s1.compareTo(s2) : 1)
  				: (s2 != null ? -1 : 0);
  	}
docs: Compares two version strings.
  
  @param v1
  @param v2
  @return