PerfClicksButton2.class.jsx

class PerfClicksButton extends PureComponent {
  constructor(props) {
    super(props);
    this.state = {
      clicks: 0,
    };
  }
  handleClick = () => {
    this.setState(({ clicks }) => ({
      clicks: clicks + 1,
    }));
  };
  render() {
    const { className, style, children } = this.props;
    const { clicks } = this.state;
    return (
      <button
        className={clsx('ClicksButton', className)}
        style={style}
        onClick={this.handleClick}
      >
        {children} {clicks}
      </button>
    );
  }
}