Build stuff into nodes! They may not do anything, but it's node-tastic!

src/main/test/net/minecraft/commands/builder/RequiredArgumentBuilderTest.java

@@ -0,0 +1,40 @@
+package net.minecraft.commands.builder;
+
+import net.minecraft.commands.arguments.CommandArgumentType;
+import net.minecraft.commands.tree.ArgumentCommandNode;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+
+import static net.minecraft.commands.arguments.IntegerArgumentType.integer;
+import static net.minecraft.commands.builder.RequiredArgumentBuilder.argument;
+import static org.hamcrest.Matchers.hasSize;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
+
+public class RequiredArgumentBuilderTest {
+    @Mock CommandArgumentType type;
+    RequiredArgumentBuilder builder;
+
+    @Before
+    public void setUp() throws Exception {
+        builder = argument("foo", type);
+    }
+
+    @Test
+    public void testBuild() throws Exception {
+        ArgumentCommandNode node = builder.build();
+
+        assertThat(node.getName(), is("foo"));
+        assertThat(node.getType(), is(type));
+    }
+
+    @Test
+    public void testBuildWithChildren() throws Exception {
+        builder.then(argument("bar", integer()));
+        builder.then(argument("baz", integer()));
+        ArgumentCommandNode node = builder.build();
+
+        assertThat(node.getChildren(), hasSize(2));
+    }
+}