code: private void checkForBlips() {
          blips.clear();
          for (Poi poi : pois.values()) {
              if (poi.distanceTo(MY_LOCATION) < this.range) {
                  if (!blips.keySet().contains(poi.getName())) {
                      blips.put(poi.getName(), poi);
                  }
              }
          }
      }
docs: Checks for poi's in the range of the radar