\n * {(state) => (\n * \n * I'm a fade Transition!\n *
\n * )}\n * \n * );\n * ```\n *\n * As noted the `Transition` component doesn't _do_ anything by itself to its child component.\n * What it does do is track transition states over time so you can update the\n * component (such as by adding styles or classes) when it changes states.\n *\n * There are 4 main states a Transition can be in:\n * - `'entering'`\n * - `'entered'`\n * - `'exiting'`\n * - `'exited'`\n *\n * Transition state is toggled via the `in` prop. When `true` the component begins the\n * \"Enter\" stage. During this stage, the component will shift from its current transition state,\n * to `'entering'` for the duration of the transition and then to the `'entered'` stage once\n * it's complete. Let's take the following example:\n *\n * ```jsx\n * state = { in: false };\n *\n * toggleEnterState = () => {\n * this.setState({ in: true });\n * }\n *\n * render() {\n * return (\n *