 resetHighlight(e) {
        areas.resetStyle(e.target);

      }

      // 3.3 add these event the layer obejct.
      function onEachFeature(feature, layer) {
        layer.on({
          mouseover: highlightFeature,
          click: zoomToFeature,
          mouseout: resetHighlight
        });
      }

      var areas = new L.TopoJSON(datasets[1], {
        style: style,
        onEachFeature: onEachFeature
      }).addTo(mymap);

      //add the control panel at the topright corner of the maps
      //c