class_docstr: A descriptor that provides a slot.
  
  This is useful for types that can't have slots via __slots__,
  e.g. tuple subclasses.
code: def __set_name__(self, cls, name):
      if self.name is not None:
          raise TypeError("already used")
      self.name = name
      try:
          slotnames = cls.__slot_names__
      except AttributeError:
          slotnames = cls.__slot_names__ = []
      slotnames.append(name)
      self._ensure___del__(cls, slotnames)
  
file_path: cpython/Tools/c-analyzer/c_common/clsutil.py
label_desc: Use image node_id 2 for calling the Slot obj's underlying member method code with example usage: obj.__set_name__(cls, name) without return types