class_docstr: CER and WER
docstr: get word error rate
code: def getWER(self):
      "get word error rate"
      return self.edWords / self.numWords
  
file_path: calamari/calamari_ocr/thirdparty/ctcwordbeamsearch/Metrics.py
imports: from __future__ import division
  from __future__ import print_function
  import re
  import editdistance
label_desc: Use image node_id 5 for calling the Metrics obj's underlying member method code with example usage: obj.getWER() and returns: unknown