class_docstr: Produces labels for BROS.
  
  First set of labels is a binary value indicating whether a token is the
  start of a group. Second set of labels is a index indicating what the next
  token in the group is.
class_docstr_tok: ["Produces","labels","for","BROS.","First","set","of","labels","is","a","binary","value","indicating","whether","a","token","is","the","start","of","a","group",".","Second","set","of","labels","is","a","index","indicating","what","the","next","token","in","the","group","is","."]
code: def pre_process_label(self, out, labels):
      pad_idx = self.lookup[self.pad_token]
      return labels, pad_idx
  
imports: from abc import ABCMeta
  import logging
  import json
  import numpy
  from finetune.encoding.target_encoders import BaseEncoder, Seq2SeqLabelEncoder, SequenceLabelingEncoder
label_desc: Use image node_id 3 for calling the BROSEncoder obj's underlying member method code with example usage: obj.pre_process_label(out, labels) and returns: labels,  pad_idx