React中怎么操作虚拟DOM的Class属性？

render() {
this.debug('render ....');
this.components.push(<AttentionScreen ref="attention" message={this.state.message} />);
this.components.forEach(function(component, index) {
if(index > 0 && !component.classList.contains('hidden')) {
component.classList.add('hidden');
}
}, this);
return (<div> { this.components } </div>);
}