content: import React, { Component } from 'react';
  
  class Foo extends Component {
    constructor(props) {
      super(props);
      this.state = {count: 0};
      setInterval(::this.tick, 1000); // bind syntax ES7
      // setInterval(this.tick.bind(this), 1000);
    }
  
    tick() {
      this.setState({ count: this.state.count + 1 });
    }
  
    render() {
      return (
        <div>
          <h1>Hello my name is React!!</h1>
          Count is {this.state.count}
        </div>
      )
    }
  }
  
  export default Foo;
  