def __im_create__(cls, mode: str=None, finalize=True, *create_args, **create_kw
    ):
    """Returns a context manager allowing the `cls` class to be instantiated

        Within the context you can set any attribute on the object,
        call any method to setup the initial state.
        Exiting the context shall finalize the object.

        * `mode`: gets set on the object as it's `__im_mode__`
        * `finalize`: the object gets finalized at the very end
        * `create_args`, `create_kw`: get passed to `cls.__im_after_create__`
          right after `cls.__init__` is called, thus allowing to set e.g.
          `creator` before the object is finalized

        """
