if (c < '0' || c > '9') break
      if (value == 0 && groupOffset != i) return false // Reject unnecessary leading '0's.
      value = value * 10 + c.code - '0'.code
      if (value > 255) return false // Value out of range.
      i++
    }
    val groupLength = i - groupOffset
    if (groupLength == 0) return false // No digits.

    // We've successfully read a byte.
    address[b++] = value.toByte()
  }

      Header("if-none-match", ""),
      Header("if-range", ""),
      Header("if-unmodified-since", ""),
      Header("last-modified", ""),
      Header("link", ""),
      Header("location", ""),
      Header("max-forwards", ""),
      Header("proxy-authenticate", ""),
      Header("proxy-authorization", ""),
      Header("range", ""),
      Header("referer", ""),
      Header("refresh", ""),