code: def _kl_exponential_exponential(dist1, dist2):
      return (
          dist1._log_lam - dist2._log_lam + dist2.lam / dist1.lam - 1.0
      )
  
imports: import chainer
  from chainer.backends import cuda
  from chainer import distribution
  from chainer.functions.array import where
  from chainer.functions.math import exponential
  from chainer.functions.math import exponential_m1
  from chainer.functions.math import logarithm_1p
  from chainer.utils import cache
label_desc: Use image node_id 1 for calling a global function with example usage: _kl_exponential_exponential(dist1, dist2) and returns: unknown