added flyweight pattern

Structural/Flyweight/Tests/FlyweightTest.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace DesignPatterns\Structural\Flyweight\Tests;
+
+use DesignPatterns\Structural\Flyweight\FlyweightFactory;
+
+/**
+ * FlyweightTest demonstrates how a client would use the flyweight structure
+ * You don't have to change the code of your client
+ */
+class FlyweightTest extends \PHPUnit_Framework_TestCase
+{
+	private $characters = array('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k',
+		'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z');
+	private $fonts = array('Arial', 'Times New Roman', 'Verdana', 'Helvetica');
+
+	// This is about the number of characters in a book of average length
+	private $numberOfCharacters = 300000;
+
+    public function testFlyweight()
+    {
+        $factory = new FlyweightFactory();
+
+        for ($i = 0; $i < $this->numberOfCharacters; $i++) {
+        	$char = $this->characters[array_rand($this->characters)];
+        	$font = $this->fonts[array_rand($this->fonts)];
+        	$flyweight = $factory->$char;
+        	// External state can be passed in like this:
+        	// $flyweight->draw($font);
+        }
+
+        // Flyweight pattern ensures that instances are shared
+        // instead of having hundreds of thousands of individual objects
+        $this->assertLessThanOrEqual($factory->totalNumber(), sizeof($this->characters));
+    }
+}