def METHOD_NAME(self):
    """Check value of similarity to self."""
    # e: (batch_size, num_heads, num_tails, d)
    # https://en.wikipedia.org/wiki/Kullback%E2%80%93Leibler_divergence#Properties
    # divergence = 0 => similarity = -divergence = 0
    # (h - t), r
    r = self._get(name="r")
    h = GaussianDistribution(mean=2 * r.mean, diagonal_covariance=0.5 * r.diagonal_covariance)
    t = GaussianDistribution(mean=r.mean, diagonal_covariance=0.5 * r.diagonal_covariance)
    sim = kullback_leibler_similarity(h=h, r=r, t=t, exact=True)
    self.assertTrue(torch.allclose(sim, torch.zeros_like(sim)), msg=f"Sim: {sim}")