code: def return_concordance_all(self, tokens: List[str]) -> List[List[str]]:
          
  
          coll = pyuca.Collator()  # type: pyuca.Collator
          tokens = sorted(tokens, key=coll.sort_key)  #! is the list order preserved?
  
          concordance_list = []  # type: List[List[str]]
          for token in tokens:
              concordance_list_for_word = self.return_concordance_word(token)  # List[str]
              if concordance_list_for_word:
                  concordance_list.append(concordance_list_for_word)
  
          return concordance_list
docs: Take a list of tokens, iteratively run each word through
          return_concordance_word and build a list of all. This returns a list
          of lists.