function makePredicate(words) {
    var wordList = words.split(" ");
    var set = Object.create(null);
    for (var i = 0; i < wordList.length; i++) {
      set[wordList[i]] = true;
    }
    return function(str) {
      return set[str] || false;
    };
  }
@param {string} words
@returns {function(*): boolean}