var overviewMapControl = new ol.control.OverviewMap({
  // see in overviewmap-custom.html to see the custom CSS used
  className: 'ol-overviewmap ol-custom-overviewmap',
  layers: [
    new ol.layer.Tile({
      source: new ol.source.OSM({
        'url': 'https://{a-c}.tile.thunderforest.com/cycle/{z}/{x}/{y}.png' +
            '?apikey=0e6fc415256d4fbb9b5166a718591d71'
      })
    })
  ],
  collapseLabel: '\u00BB',
  label: '\u00AB',
  collapsed: false
});

var map = new ol.Map({
  controls: ol.control.defaults().extend([
    overviewMapControl
  ]),
  interactions: ol.interaction.defaults().extend([
    new ol.interaction.DragRotateAndZoom()
  ]),
  layers: [
    new ol.layer.Tile({
      source: new ol.source.OSM()
    })
  ],
  target: 'map',
  view: new ol.View({
    center: [500000, 6000000],
    zoom: 7
  })
});
