def inertia_tensor(self):
        """
        The inertia tensor of the source for the rotation around its
        center of mass.
        """

        mu = self.moments_central
        a = mu[0, 2]
        b = -mu[1, 1]
        c = mu[2, 0]
        return np.array([[a, b], [b, c]]) * u.pix**2
The inertia tensor of the source for the rotation around its
        center of mass.