Add SubCommand

SpigotCore_Main/src/de/steamwar/command/SubCommand.java

@@ -89,6 +89,9 @@ class SubCommand {
     private GuardChecker getGuardChecker(Parameter parameter, Map<String, GuardChecker> localGuardChecker) {
         SWCommand.Guard guard = parameter.getAnnotation(SWCommand.Guard.class);
         if (guard != null) {
+            if (guard.value() == null || guard.value().isEmpty()) {
+                return GUARD_FUNCTIONS.getOrDefault(parameter.getType().getTypeName(), null);
+            }
             GuardChecker current = localGuardChecker.getOrDefault(guard.value(), GUARD_FUNCTIONS.getOrDefault(guard.value(), null));
             if (guardChecker == null) {
                 Bukkit.getLogger().log(Level.WARNING, () -> "The guard checker with name '" + guard.value() + "' is neither a local guard checker nor a global one");