componentWillUnmount() {
    // Stop animating
    this.setState({
      animPlay: false,
      cells: []
    });
  }
/**
   * When the component is about to unmount
   */
When the component is about to unmount
When the component is about to unmount
componentWillUnmount() {
    this.setState({
      animPlay: false,
      cells: []
    });
  }
componentWillUnmount ( ) { this . setState ( { animPlay : false , cells : [ ] } ) ; }
When the component is about to unmount
When the component is about to unmount
// Stop animating