constructor (props) {
        super(props);
        this.toggleMenu = this.toggleMenu.bind(this);
        this.showSidebar = this.showSidebar.bind(this);
        this.resize = this.resize.bind(this);
        this.toggleMenuByClick = this.toggleMenuByClick.bind(this);
        this.showSidebarByClick = this.showSidebarByClick.bind(this);
        this.state = {
            toggleMenu: false,
            showSidebar: false,
            height: 'auto'
        };
    }class MyClass {
  foo = () => {
    console.log('foo a = ', this.a);
  }
  bar = () => {
    this.a = 10;
    setTimeout(this.foo, 10); // Мы не биндим foo на this
  }
}
const o = new MyClass();
const bar = o.bar; // и тут тоже не биндим
bar(); // выводит "foo a = 10"      
  
  onMouseMoveHandler = (e) => {
    if (this.state.active) {
    ....