class_docstr: A non-data descriptor that makes a value only visible on the class.
  
  This is like the "classmethod" builtin, but does not show up on
  instances of the class.  It may be used as a decorator.
code: def __set_name__(self, cls, name):
      if self.name is not None:
          raise TypeError("already used")
      self.name = name
  
file_path: cpython/Tools/c-analyzer/c_common/clsutil.py
label_desc: Use image node_id 2 for calling the classonly obj's underlying member method code with example usage: obj.__set_name__(cls, name) without return types