How to add Google basemaps in openlayers-3?

In openlayers-2, we can add google basemaps(satellite,physical,hybrid,etc.). I need to add google basemaps in openlayer-3. How can I add google basemaps??? CODE in openlayers-3 ``` map = new ol.Map({ layers: [ new ol.layer.Group({ layers: [ new ol.layer.Tile({ source: null, visible:false }), new ol.layer.Tile({ source: new ol.source.MapQuest({layer: 'sat'}) }), new ol.layer.Tile({ source: new ol.source.OSM(), visible:false }) ]}) ], target: 'map', view: new ol.View({ center:[28.566667, 4.01666699999998], zoom:7 }), controls: ol.control.defaults({ attribution:false }).extend([ scaleLineControl ]), }); lyr=new ol.layer.Tile({ source: new ol.source.TileWMS({ url: 'http://localhost:8080/geoserver/wms', params: {'LAYERS': 'test:test', 'TILED': true}, serverType: 'geoserver' }) }); map.addLayer(lyr); ``` I need to google basemaps instead of osm and mapquest.