code: def create_ment_id(
      mention_x: MentionData, mention_y: MentionData
  ) -> str:
      return "_".join(
          [mention_x.get_mention_id(), mention_y.get_mention_id()]
      )
  
file_path: nlp-architect/nlp_architect/data/cdc_resources/relations/within_doc_coref_extraction.py
imports: import logging
  import os
  from typing import List, Set
  from nlp_architect.common.cdc.mention_data import MentionData
  from nlp_architect.data.cdc_resources.relations.relation_extraction import RelationExtraction
  from nlp_architect.data.cdc_resources.relations.relation_types_enums import RelationType
  from nlp_architect.utils.io import load_json_file
label_desc: Use image node_id 7 for calling the WithinDocCoref obj's underlying member method code with example usage: obj.create_ment_id(mention_x, mention_y) and returns: str