def compute_moments_and_cgf(self, phi, mask=True):
        u0 = np.exp(phi[0])
        u = [u0]
        g = -u0
        return (u, g)
Compute the moments and :math:`g(\phi)`.
dataset/ETHPy150Open bayespy/bayespy/bayespy/inference/vmp/nodes/poisson.py/PoissonDistribution.compute_moments_and_cgf