describe('StackOf Type', function() {
    it('should support the stackOf propTypes', function() {
      typeCheckPass(PropTypes.stackOf(React.PropTypes.number), Immutable.Stack([1, 2, 3]));
      typeCheckPass(PropTypes.stackOf(React.PropTypes.string), Immutable.Stack(['a', 'b', 'c']));
      typeCheckPass(PropTypes.stackOf(React.PropTypes.oneOf(['a', 'b'])), Immutable.Stack(['a', 'b']));