* k) worst case.
   */
  private void trim() {
    int left = 0;
    int right = 2 * k - 1;

    int minThresholdPosition = 0;
    // The leftmost position at which the greatest of the k lower elements
    // -- the new value of threshold -- might be found.

    int iterations = 0;
    int maxIterations = IntMath.log2(right - left, RoundingMode.CEILING) * 3;

  /**
   * If a hostname is not a key in the EXCLUDE map, and if removing its leftmost component results
   * in a name which is a key in this map, it is a public suffix.
   */
  public static final ImmutableMap<String, PublicSuffixType> UNDER =
      TrieParser.parseTrie(