code: public static double distance(@NonNull Point point1, @NonNull Point point2) {
      return distance(point1, point2, TurfConstants.UNIT_DEFAULT);
    }
docs: Calculates the distance between two points in kilometers. This uses the Haversine formula to
  account for global curvature.
  
  @param point1 first point used for calculating the bearing
  @param point2 second point used for calculating the bearing
  @return distance between the two points in kilometers
  @see <a href="http://turfjs.org/docs/#distance">Turf distance documentation</a>
  @since 1.2.0