// will look like: [foo, bar, com], [bar, com], [com]. The longest matching rule wins.
    var exactMatch: String? = null
    for (i in domainLabelsUtf8Bytes.indices) {
      val rule = publicSuffixListBytes.binarySearch(domainLabelsUtf8Bytes, i)
      if (rule != null) {
        exactMatch = rule
        break
      }
    }