code: def get_node_pos(self, string_key):
          
          if not self.ring:
              return None
  
          key = self.gen_key(string_key)
  
          nodes = self._sorted_keys
          pos = bisect(nodes, key)
  
          if pos == len(nodes):
              return 0
          else:
              return pos
docs: Given a string key a corresponding node in the hash ring is returned
          along with it's position in the ring.
  
          If the hash ring is empty, (`None`, `None`) is returned.