function SuffixTrie(rules) {
  this.exceptions = Object.create(null);
  this.rules = Object.create(null);

  if (rules) {
    for (var i = 0; i < rules.length; i += 1) {
      var rule = rules[i];
      if (rule.exception) {
        insertInTrie(rule, this.exceptions);
      } else {
        insertInTrie(rule, this.rules);
      }
    }
  }
}
Contains the public suffix ruleset as a Trie for efficient look-up.

@constructor