code: def get_ref(obj):
      
      oid = id(obj)
      try:
          server.id2ref[oid] = obj
      except TypeError:
          server.id2obj[oid] = obj
      return str(oid)
docs: Get string reference to object. Stores a weak reference in a dictionary
      using the object's id as the key. If the object cannot be weakly
      referenced (e.g. dictionaries, frame objects), store a strong references
      in a classic dictionary.
  
      Returns the object's id as a string.