It seems like those were intended to be public APIs (https://github.com/facebook/react/pull/10629) but they’re not published on npm because `lib` folder is not in the `"files"` whitelist.
/**
   * Initialize state members.
   */
  state = {degrees: 0, velocity: 0, drag: MOUSE_UP_DRAG};
  /**
   * When the component is mounted into the document - this is similar to a
   * constructor, but invoked when the instance is actually mounted into the
   * document. Here's, we'll just set up an animation loop that invokes our
   * method. Binding of `this.onTick` is not needed because all React methods
   * are automatically bound before being mounted.
   */
  componentDidMount() {