def join(self, t2, unique=False):
        """
        Join this triangulation with another. If the points are known to have no duplicates, then
        set unique=True to skip the testing and duplicate removal
        """

        lonv1 = np.concatenate((self.lons, t2.lons), axis=0)
        latv1 = np.concatenate((self.lats, t2.lats), axis=0)

        ## remove any duplicates

        if not unique:
            lonv1, latv1 = remove_duplicate_lonlat(lonv1, latv1)

        return lonv1, latv1
Join this triangulation with another. If the points are known to have no duplicates, then
        set unique=True to skip the testing and duplicate removal