@staticmethod
def compute_filling_factor(surface_potential, lagrangian_points):
    """
        Compute filling factor of given BinaryStar system.
        Filling factor is computed as::

            (Omega_{inner} - Omega) / (Omega_{inner} - Omega_{outter}),

        where Omega_X denote potential value and `Omega` is potential of given Star.
        Inner and outter are critical inner and outter potentials for given binary star system.

        :param surface_potential: float;
        :param lagrangian_points: List; lagrangian points in `order` (in order to ensure that L2)
        :return: float;
        """
    return (lagrangian_points[1] - surface_potential) / (lagrangian_points[
        1] - lagrangian_points[2])
