code: function raises(fn, errorValidator) {
      check.verify.fn(fn, 'expected function that raises');
      try {
        fn();
      } catch (err) {
        if (typeof errorValidator === 'undefined') {
          return true;
        }
        if (typeof errorValidator === 'function') {
          return errorValidator(err);
        }
        return false;
      }
      // error has not been raised
      return false;
    }
docs: Checks if given function raises an error
  
  @method raises