code: def _kl_dirichlet_dirichlet(dist1, dist2):
      return (
          -_lbeta(dist1.alpha)
          + _lbeta(dist2.alpha)
          + sum_mod.sum(
              (dist1.alpha - dist2.alpha)
              * (
                  digamma.digamma(dist1.alpha)
                  - expand_dims.expand_dims(
                      digamma.digamma(dist1.alpha0), axis=-1
                  )
              ),
              axis=-1,
          )
      )
  
imports: import numpy
  import chainer
  from chainer import distribution
  from chainer.functions.array import expand_dims
  from chainer.functions.math import digamma
  from chainer.functions.math import exponential
  from chainer.functions.math import lgamma
  from chainer.functions.math import sum
  from chainer.utils import cache
label_desc: Use image node_id 2 for calling a global function with example usage: _kl_dirichlet_dirichlet(dist1, dist2) and returns: unknown