code: def Bayesian_gap(self):
      return 1.0 - self._sum_by_parts(lambda s: self._Elog(s).exp())
  
imports: import collections
  import functools
  import io
  import os
  import warnings
  import dgl
  import numpy
  import scipy
  import torch
label_desc: Use image node_id 9 for calling the _Dirichlet obj's underlying member method code with example usage: obj.Bayesian_gap() and returns: unknown