code: def update_lang(self,
                      lang: Optional[Text],
                      data: List[Tuple[Text, Text]],
                      flags: Flags):
          
  
          sd = SortingDict()
  
          for item in (self.parse_item(x[0], x[1], flags) for x in data):
              if item:
                  sd.append(item)
  
          if lang not in self.dict:
              self.dict[lang] = {}
  
          d = self.dict[lang]
  
          for k, v in sd.extract().items():
              if k not in d:
                  d[k] = SentenceGroup()
  
              d[k].update(v, flags)
docs: Update translations for one specific lang