A map operation was attempted with a key that does not exist in the map, such as using the `#{ key := Value }` update syntax with a missing key. The missing key is included as `{badkey, Key}`.
badkey
erlang A map operation was attempted with a key that does not exist in the map, such as using the `#{ key := Value }` update syntax with a missing key. The missing key is included as `{badkey, Key}`.