如何使用带有JSON字符串的Google map.data.loadGeoJson？

var jsonData = {
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {
        "name": "New York"
      },
      "geometry": {
        "type": "Point",
        "coordinates": [-74.0060, 40.7128]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "name": "San Francisco"
      },
      "geometry": {
        "type": "Point",
        "coordinates": [-122.4194, 37.7749]
      }
    }
  ]
};

var dataLayer = new google.maps.Data();
dataLayer.loadGeoJson(jsonData);

dataLayer.setMap(map);