code: def _min_depth(self):
          
          if "min_depth" in self.__dict__:
              return self.__dict__["min_depth"]
  
          min_depth = 0
          hypernyms = self.hypernyms()
          if hypernyms:
              min_depth = 1 + min(h._min_depth() for h in hypernyms)
          self.__dict__["min_depth"] = min_depth
  
          return min_depth
docs: Finds minimum path length from the root.
  
          Notes
          -----
            Internal method. Do not call directly.
  
          Returns
          -------
            int
          Minimum path length from the root.