code: function() {
    this.words = {};
    this.tags = tags;
    this.regex = [];
    this.patterns = {};
    this.conjugations = {};
    this.plurals = {};
    //denormalized data for faster-lookups
    this.cache = {
      firstWords: {},
      toInfinitive: {},
      toSingular: {}
    };
  }
docs: class World