UNSAFE_componentWillMount() {}
        UNSAFE_componentWillUpdate() {}
        render() {
          return (
            <div>
              <Wrapper>
                <Foo />
              </Wrapper>
              <div>
                <Bar />
                <Foo />
              </div>
            </div>
          );
        }
      }
      function Wrapper({children}) {
        return <div>{children}</div>;
      }
      class Foo extends React.Component {
        UNSAFE_componentWillReceiveProps() {}
        render() {
          return null;
        }
      }
      class Bar extends React.Component {