class_docstr: optical score of beam
code: def __init__(self, prBlank=0, prNonBlank=0):
      self.prBlank = prBlank  # prob of ending with a blank
      self.prNonBlank = prNonBlank
  
imports: from __future__ import division
  from __future__ import print_function
  import copy
label_desc: Use image node_id 1 to create a new Optical object  with example: obj = Optical(prBlank, prNonBlank)