docs: public static int levenshteinDistance(String o1, String o2) {
      // Let o1 be the shorter one:
      if(o1.length() > o2.length()) {
        return levenshteinDistance(o2, o1);
      }
      final int l1 = o1.length(), l2 = o2.length();
      // Exploit that Java caches the hash code of strings:
      if(l1 == l2 && o1.hashCode() == o2.hashCode() && o1.equals(o2)) {
        return 0;
      }
      // Determine prefix and postfix lengths:
      final int prefix = prefixLen(o1, o2);
      if(prefix == l1 || prefix == l2) {
        return Math.abs(l1 - l2);
      }
      final int postfix = postfixLen(o1, o2, prefix);
      return // Prefix and postfix are a complete object:
      (prefix + postfix == l1 || prefix + postfix == l2) ? Math.abs(l1 - l2) : //
      // Exactly one char difference optimization:
          (l1 == l2 && prefix + postfix + 1 == l1) ? 1 : //
          // Default case, compute
              levenshteinDistance(o1, o2, prefix, postfix);
    }