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

@@ -30,6 +30,7 @@ import java.util.stream.Collectors;
 
 public class Argument<T> {
 
+    public static final Argument<Boolean> BOOLEAN = new Argument<>(ArgumentType.BOOLEAN, bool -> true);
     public static final Argument<Integer> INT = new Argument<>(ArgumentType.INT, integer -> true);
     public static final Argument<Long> LONG = new Argument<>(ArgumentType.LONG, l -> true);
     public static final Argument<Float> FLOAT = new Argument<>(ArgumentType.FLOAT, f -> true);

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

@@ -25,6 +25,7 @@ import java.util.function.Function;
 
 public class ArgumentType<T> {
 
+    public static final ArgumentType<Boolean> BOOLEAN = new ArgumentType<>(Boolean::parseBoolean, false);
     public static final ArgumentType<Integer> INT = new ArgumentType<>(Integer::parseInt, true);
     public static final ArgumentType<Long> LONG = new ArgumentType<>(Long::parseLong, true);
     public static final ArgumentType<Float> FLOAT = new ArgumentType<>(Float::parseFloat, true);