char c0 = input.charAt(i);
        char c1 = input.charAt(i + 1);
        char c2 = input.charAt(i + 2);
        char c3 = input.charAt(i + 3);
        if (c0 < 0x80 && c1 < 0x80 && c2 < 0x80 && c3 < 0x80) {
          int k1 = c0 | (c1 << 8) | (c2 << 16) | (c3 << 24);
          k1 = mixK1(k1);
          h1 = mixH1(h1, k1);
          i += 4;
          len += 4;
        } else {
          break;
        }

                retValue = retValue.substring(2);

                if (retValue.length() >= 2 && (retValue.charAt(1) == '|' || retValue.charAt(1) == ':')) {
                    // special case: if there is a windows drive letter, then keep the original return value
                    retValue = retValue.charAt(0) + ":" + retValue.substring(2);
                } else {
                    // Now we expect the host

    checkNotNull(a);
    checkNotNull(b);

    int maxPrefixLength = Math.min(a.length(), b.length());
    int p = 0;
    while (p < maxPrefixLength && a.charAt(p) == b.charAt(p)) {
      p++;
    }
    if (validSurrogatePairAt(a, p - 1) || validSurrogatePairAt(b, p - 1)) {
      p--;
    }
    return a.subSequence(0, p).toString();
  }

  /**

                continue;
            }

            char ch = s.charAt(pos);
            pos++;
            if (ch == '\\') {
                sb.append(ch);
                if (pos >= end) {
                    break; // ERROR, or let it go?
                }
                ch = s.charAt(pos);
                pos++;
            }

            sb.append(ch);
        }

    if (chars instanceof String) {
      return toLowerCase((String) chars);
    }
    char[] newChars = new char[chars.length()];
    for (int i = 0; i < newChars.length; i++) {
      newChars[i] = toLowerCase(chars.charAt(i));
    }
    return String.valueOf(newChars);
  }

  /**
   * If the argument is an {@linkplain #isUpperCase(char) uppercase ASCII character}, returns the

        }
      }
    }
    if (ipString.charAt(0) == IPV6_DELIMITER && ipString.charAt(1) != IPV6_DELIMITER) {
      return null; // ^: requires ^::
    }
    if (ipString.charAt(ipString.length() - 1) == IPV6_DELIMITER
        && ipString.charAt(ipString.length() - 2) != IPV6_DELIMITER) {
      return null; // :$ requires ::$
    }

    if (chars instanceof String) {
      return toLowerCase((String) chars);
    }
    char[] newChars = new char[chars.length()];
    for (int i = 0; i < newChars.length; i++) {
      newChars[i] = toLowerCase(chars.charAt(i));
    }
    return String.valueOf(newChars);
  }

  /**
   * If the argument is an {@linkplain #isUpperCase(char) uppercase ASCII character}, returns the

    checkNotNull(a);
    checkNotNull(b);

    int maxPrefixLength = Math.min(a.length(), b.length());
    int p = 0;
    while (p < maxPrefixLength && a.charAt(p) == b.charAt(p)) {
      p++;
    }
    if (validSurrogatePairAt(a, p - 1) || validSurrogatePairAt(b, p - 1)) {
      p--;
    }
    return a.subSequence(0, p).toString();
  }

  /**

        l1 = path1.length() - p1;
        l2 = path2.length() - p2;

        // anything with dots voids comparison
        if ( l1 > 1 && path1.charAt(p1 + 1) == '.' )
            return true;
        if ( l2 > 1 && path2.charAt(p2 + 1) == '.' )
            return true;

        return l1 == l2 && path1.regionMatches(true, p1, path2, p2, l1);
    }


    /**
     * 

        StringItem stringPart;

        Item digitPart;

        CombinationItem(String value) {
            int index = 0;
            for (int i = 0; i < value.length(); i++) {
                char c = value.charAt(i);
                if (Character.isDigit(c)) {
                    index = i;
                    break;
                }
            }