code: def __init__(self, tokenizer, source_prefix):
      self.tokenizer = tokenizer
      self.source_prefix = source_prefix
      self.source_prefix_tokenized = (
          tokenizer.encode(source_prefix, add_special_tokens=False)
          if source_prefix
          else []
      )
  
file_path: DeepKE/src/deepke/name_entity_re/cross/seq2seq/constraint_decoder/constraint_decoder.py
imports: from collections import defaultdict
  import os
  from typing import List
label_desc: Use image node_id 1 to create a new ConstraintDecoder object  with example: obj = ConstraintDecoder(tokenizer, source_prefix)