code: function findContainerNodes( target ) {
    return ( memo, instance ) => {
      try {
        const node = ReactDOM.findDOMNode( instance );
        if ( node && ( node === target || node.contains( target ) ) ) {
          memo.push( { instance, node } );
        }
      } finally {
        return memo;
      }
    };
  }
docs: findContainerNodes: Called by our click handler to find instances with nodes
  that are equal to or that contain the click target. Any that pass this test
  will be recipients of the next keydown event.
  
  @access public
  @param {object} target The click event.target DOM element
  @return {function} Reducer function