def d3logpdf_dlink3(self, link_f, y, Y_metadata=None):
d3lik_dlink3 = <NUM_LIT:2>*y/(link_f)**<NUM_LIT:3><EOL>return d3lik_dlink3<EOL>
Third order derivative log-likelihood function at y given link(f) w.r.t link(f)

.. math::
    \\frac{d^{3} \\ln p(y_{i}|\lambda(f_{i}))}{d^{3}\\lambda(f)} = \\frac{2y_{i}}{\\lambda(f_{i})^{3}}

:param link_f: latent variables link(f)
:type link_f: Nx1 array
:param y: data
:type y: Nx1 array
:param Y_metadata: Y_metadata which is not used in poisson distribution
:returns: third derivative of likelihood evaluated at points f
:rtype: Nx1 array