class_docstr: Implements an cross-entropy expectation semiring.
  
  Computes both the log-values of two distributions and the running cross entropy between two distributions.
  
  Based on descriptions in:
  
  * Parameter estimation for probabilistic finite-state transducers :cite:`eisner2002parameter`
  * First-and second-order expectation semirings with applications to minimum-risk training on translation forests :cite:`li2009first`
  * Sample Selection for Statistical Grammar Induction :cite:`hwa2000samplesf`
code: def size():
      return 3
  
imports: import torch
label_desc: Use image node_id 1 for calling the CrossEntropySemiring obj's underlying member method code with example usage: obj.size() and returns: int