docs: private Overlay createPolygon(BoundingBox key, Integer value, int redthreshold, int orangethreshold) {
          Polygon polygon = new Polygon(mMapView);
          if (value < orangethreshold)
              polygon.setFillColor(Color.parseColor(alpha + yellow));
          else if (value < redthreshold)
              polygon.setFillColor(Color.parseColor(alpha + orange));
          else if (value >= redthreshold)
              polygon.setFillColor(Color.parseColor(alpha + red));
          else {
              //no polygon
          }
          polygon.setStrokeColor(polygon.getFillColor());
  
          //if you set this to something like 20f and have a low alpha setting,
          // you'll end with a gaussian blur like effect
          polygon.setStrokeWidth(0f);
          List<GeoPoint> pts = new ArrayList<GeoPoint>();
          pts.add(new GeoPoint(key.getLatNorth(), key.getLonWest()));
          pts.add(new GeoPoint(key.getLatNorth(), key.getLonEast()));
          pts.add(new GeoPoint(key.getLatSouth(), key.getLonEast()));
          pts.add(new GeoPoint(key.getLatSouth(), key.getLonWest()));
          polygon.setPoints(pts);
          return polygon;
      }