code: def mounted(cls, unmounted):  # noqa: N802
          
          assert isinstance(unmounted, UnmountedType), ("{} can't mount {}").format(
              cls.__name__, repr(unmounted)
          )
  
          return cls(
              unmounted.get_type(),
              *unmounted.args,
              _creation_counter=unmounted.creation_counter,
              **unmounted.kwargs
          )
docs: Mount the UnmountedType instance