code: function _Utils_eq(x, y) {
      for (
        var pair, stack = [], isEqual = _Utils_eqHelp(x, y, 0, stack);
        isEqual && (pair = stack.pop());
        isEqual = _Utils_eqHelp(pair.a, pair.b, 0, stack)
      ) {}
  
      return isEqual;
    }
docs: EQUALITY