it was created the Structural namespace and append its patterns

Structural/Composite/CompositeTest.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace DesignPatterns\Test\Composite;
+
+use DesignPatterns\Structural\Composite;
+
+/**
+ * FormTest tests the composite pattern on Form
+ */
+class CompositeTest extends \PHPUnit_Framework_TestCase
+{
+
+    public function testRender()
+    {
+        $form = new Composite\Form();
+        $form->addElement(new Composite\TextElement());
+        $form->addElement(new Composite\InputElement());
+        $embed = new Composite\Form();
+        $embed->addElement(new Composite\TextElement());
+        $embed->addElement(new Composite\InputElement());
+        $form->addElement($embed);  // here we have a embedded form (like SF2 does)
+
+        $this->assertRegExp('#^\s{4}#m', $form->render());
+    }
+
+    /**
+     * The all point of this pattern, a Composite must inherit from the node
+     * if you want to builld trees
+     */
+    public function testFormImplementsFormEelement()
+    {
+        $this->assertTrue(is_subclass_of('DesignPatterns\Structural\Composite\Form', 'DesignPatterns\Structural\Composite\FormElement'));
+    }
+}