code: def extract_edus(merge_file_str):
          
          lines = merge_file_str.splitlines()
  
          edus = defaultdict(list)
          for line in lines:
              if line.strip():  # ignore empty lines
                  token = line.split('\t')[2]
                  edu_id = int(line.split('\t')[9])
                  edus[edu_id].append(token)
          return edus
docs: Extract EDUs from DPLPs .merge output files.
  
          Returns
          -------
          edus : dict from EDU IDs (int) to words (list(str))