class TodoItem extends React.Componennt {
  render() {
    const {
      content,
      completed
    } = this.props;

    return (
      <div>
        <input type="checkbox" checked={completed} />
        <span>{content}</span>
        <button>x</button>
      </div>
    );
  }
}

TodoItem.defaultProps = {
  completed: false
};

TodoItem.propTypes = {
  content: React.PropTypes.string.isRequired,
  completed: React.PropTypes.bool
};