optional
fun <T : Any> optional(name: String, type: ArgumentType<T>, default: Nothing? = null, suggests: SuggestionProvider<ClientCommandSource>? = null, block: CmdChainScope.ArgContinuation<T?>)
Appends an optional argument. Omitted values are resolved from the declared default; all following arguments must also be optional.
fun <T : Any> optional(name: String, type: ArgumentType<T>, default: T, suggests: SuggestionProvider<ClientCommandSource>? = null, block: CmdChainScope.ArgContinuation<T>)
Appends an optional argument with a non-null default.