const Foobar = () => (
  <Map
    {...viewport}
    mapStyle="mapbox://styles/mapbox/dark-v9"
    onViewportChange={onChangeViewport}>
    <div className="map-navigation-control">
      <NavigationControl onViewportChange={onChangeViewport} />
    </div>
    <Line
      coords={[
        [-79.995886, 40.440625],
        [-87.629798, 41.878114],
      ]} />
    {locations}
  </Map>
)