code: def extendByBlanks(seq, b):
      """extends a label seq. by adding blanks at the beginning, end and in between each label"""
      res = [b]
      for s in seq:
          res.append(s)
          res.append(b)
      return res
  
file_path: calamari/calamari_ocr/ocr/model/ctcdecoder/token_passing_ctc_decoder.py
imports: import math
  import numpy
  from calamari_ocr.ocr.model.ctcdecoder.ctc_decoder import CTCDecoder
label_desc: Use image node_id 1 for calling a global function with example usage: extendByBlanks(seq, b) and returns: res