geolocation search query returned via data streams

geodragdatastream.js

this.getDragData = function(lat, lng) {
  return appbaseRef.search({
    type: 'city',
    body: {
      query: {
        filter: {
          geo_distance: {
            distance: "2000km",
            location: [lat, lng]
          }
        }
      }
    }
  });
}