// inside getData function, after geojson has been generated

geojson.metadata.fields = [
  { name: 'AgencyID', type: 'Integer' },
  { name: 'IncidentNumber' type: 'String' },
  // add all properties return by PulsePoint when Active Calls > 0
]

geojson.metadata.extent = {
    "xmin": -118.25740500499995,
    "ymin": 34.11760799600006,
    "xmax": -118.06609300499997,
    "ymax": 34.23500699500005,
    "spatialReference": {
      "wkid": 4326,
      "latestWkid": 4326
    }
  }