Made ArgumentBuilders use a RootCommandNode to hold their arguments

src/main/java/net/minecraft/commands/builder/ArgumentBuilder.java

@@ -1,24 +1,24 @@
 package net.minecraft.commands.builder;
 
-import com.google.common.collect.Lists;
 import net.minecraft.commands.Command;
 import net.minecraft.commands.tree.CommandNode;
+import net.minecraft.commands.tree.RootCommandNode;
 
 import java.util.List;
 
 public abstract class ArgumentBuilder<T extends ArgumentBuilder<?>> {
-    private final List<ArgumentBuilder> arguments = Lists.newArrayList();
+    private final RootCommandNode arguments = new RootCommandNode();
     private Command command;
 
     protected abstract T getThis();
 
     public T then(ArgumentBuilder argument) {
-        arguments.add(argument);
+        arguments.addChild(argument.build());
         return getThis();
     }
 
-    public List<ArgumentBuilder> getArguments() {
-        return arguments;
+    public List<CommandNode> getArguments() {
+        return arguments.getChildren();
     }
 
     public T executes(Command command) {

src/main/java/net/minecraft/commands/builder/LiteralArgumentBuilder.java

@@ -1,5 +1,6 @@
 package net.minecraft.commands.builder;
 
+import net.minecraft.commands.tree.CommandNode;
 import net.minecraft.commands.tree.LiteralCommandNode;
 
 public class LiteralArgumentBuilder extends ArgumentBuilder<LiteralArgumentBuilder> {
@@ -26,8 +27,8 @@ public class LiteralArgumentBuilder extends ArgumentBuilder<LiteralArgumentBuild
     public LiteralCommandNode build() {
         LiteralCommandNode result = new LiteralCommandNode(getLiteral(), getCommand());
 
-        for (ArgumentBuilder argument : getArguments()) {
-            result.addChild(argument.build());
+        for (CommandNode argument : getArguments()) {
+            result.addChild(argument);
         }
 
         return result;

src/main/java/net/minecraft/commands/builder/RequiredArgumentBuilder.java

@@ -2,6 +2,7 @@ package net.minecraft.commands.builder;
 
 import net.minecraft.commands.arguments.CommandArgumentType;
 import net.minecraft.commands.tree.ArgumentCommandNode;
+import net.minecraft.commands.tree.CommandNode;
 
 public class RequiredArgumentBuilder<T> extends ArgumentBuilder<RequiredArgumentBuilder<T>> {
     private final String name;
@@ -32,8 +33,8 @@ public class RequiredArgumentBuilder<T> extends ArgumentBuilder<RequiredArgument
     public ArgumentCommandNode<T> build() {
         ArgumentCommandNode<T> result = new ArgumentCommandNode<T>(getName(), getType(), getCommand());
 
-        for (ArgumentBuilder argument : getArguments()) {
-            result.addChild(argument.build());
+        for (CommandNode argument : getArguments()) {
+            result.addChild(argument);
         }
 
         return result;

src/test/java/net/minecraft/commands/builder/ArgumentBuilderTest.java

@@ -25,7 +25,7 @@ public class ArgumentBuilderTest {
         builder.then(argument);
 
         assertThat(builder.getArguments(), hasSize(1));
-        assertThat(builder.getArguments(), hasItems((ArgumentBuilder) argument));
+        assertThat(builder.getArguments(), hasItems((CommandNode) argument.build()));
     }
 
     private static class TestableArgumentBuilder extends ArgumentBuilder<TestableArgumentBuilder> {