code: def merge_subtokens(doc, label="subtok"):
      
      merger = Matcher(doc.vocab)
      merger.add("SUBTOK", None, [{"DEP": label, "op": "+"}])
      matches = merger(doc)
      spans = [doc[start : end + 1] for _, start, end in matches]
      with doc.retokenize() as retokenizer:
          for span in spans:
              retokenizer.merge(span)
      return doc
docs: Merge subtokens into a single token.
  
      doc (Doc): The Doc object.
      label (unicode): The subtoken dependency label.
      RETURNS (Doc): The Doc object with merged subtokens.
  
      DOCS: https://spacy.io/api/pipeline-functions#merge_subtokens