Popover timeout clearing

Popover.jsx

  componentWillReceiveProps(nextProps) {
    if (nextProps.open !== this.state.open) {
      // (...)
      } else {
        if (nextProps.animated) {
          if (this.timeout !== null) return;    // Return if still closing
          this.setState({closing: true});
  // (...)
  
  componentWillUnmount() {
    clearTimeout(this.timeout);
    this.timeout = null;                        // Clear timeout attribute
  }