code: private static boolean betweenLongitudes(double topLeftLon, double bottomRightLon, double lon) {
          if (topLeftLon <= bottomRightLon)
              return lon >= topLeftLon && lon <= bottomRightLon;
          else
              return lon >= topLeftLon || lon <= bottomRightLon;
      }
docs: Returns true if and only if lon is between the longitudes topLeftLon and
  bottomRightLon.
  
  @param topLeftLon
  must be between -180 and 180
  @param bottomRightLon
  must be between -180 and 180
  @param lon
  must be between -180 and 180
  @return