existingArguments property
latefinal
A map containing the arguments and the values that the user has inputted so far.
The keys of this map depend on the names of the arguments set in command. If a user has not yet filled in an argument, it will not be present in this map.
The values might contain partial data.
Implementation
late final Map<String, String> existingArguments = Map.fromEntries(
interaction.data.options!.map((option) => MapEntry(option.name, option.value.toString())),
);