docs: function listFeatures(call) {
    var lo = call.request.getLo();
    var hi = call.request.getHi();
    var left = _.min([lo.getLongitude(), hi.getLongitude()]);
    var right = _.max([lo.getLongitude(), hi.getLongitude()]);
    var top = _.max([lo.getLatitude(), hi.getLatitude()]);
    var bottom = _.min([lo.getLatitude(), hi.getLatitude()]);
    // For each feature, check if it is in the given bounding box
    _.each(feature_list, function(feature) {
      if (feature.getName() === '') {
        return;
      }
      if (feature.getLocation().getLongitude() >= left &&
          feature.getLocation().getLongitude() <= right &&
          feature.getLocation().getLatitude() >= bottom &&
          feature.getLocation().getLatitude() <= top) {
        call.write(feature);
      }
    });
    call.end();
  }