@lru_cache(maxsize=1)
def id(self) -> List[int]:
    "Retrieves the list of element IDs as returned by `__call__`\n\n        Parameters\n        ----------\n\n        Returns\n        -------\n        list of int\n            List of element IDs.\n\n        Notes\n        -----\n        The result of this method is cached, so that multiple calls\n        to it won't result in multiple calculations. If the mesh\n        is modified and the cache is not properly clear the calls\n        to this method can result in invalid return values.\n        "
    return list(self().keys())
Retrieves the list of element IDs as returned by `__call__`

Parameters
----------

Returns
-------
list of int
    List of element IDs.

Notes
-----
The result of this method is cached, so that multiple calls
to it won't result in multiple calculations. If the mesh
is modified and the cache is not properly clear the calls
to this method can result in invalid return values.
@lru_cache(maxsize=1)
def id(self) -> List[int]:
    "Retrieves the list of element IDs as returned by `__call__`\n\n        Parameters\n        ----------\n\n        Returns\n        -------\n        list of int\n            List of element IDs.\n\n        Notes\n        -----\n        The result of this method is cached, so that multiple calls\n        to it won't result in multiple calculations. If the mesh\n        is modified and the cache is not properly clear the calls\n        to this method can result in invalid return values.\n        "
    return list(self().keys())