docs: def set_annotations(cls, __fn, *notes, **keyword_notes):
          """Set the annotations on the given callable."""
          if hasattr(__fn, '__func__'):
              __fn = __fn.__func__
          if hasattr(__fn, '__notes__'):
              msg = 'callable already has notes: {!r}'
              raise AttributeError(msg.format(__fn))
          __fn.__notes__ = (notes, keyword_notes)