Function unmount

packages/react-test-renderer/src/ReactTestRenderer.js:585–593

()

      updateContainer(newElement, root, null, null);
    },
    unmount() {
      if (root == null || root.current == null) {
        return;
      }
      updateContainer(null, root, null, null);
      // $FlowFixMe[incompatible-type] found when upgrading Flow
      container = null;
      root = null;
    },
    getInstance() {
      if (root == null || root.current == null) {
        return null;