Added a new associate method, to associate a row in the cart with a model, so you can access the model from the CartRowCollection

tests/helpers/SessionMock.php

@@ -0,0 +1,17 @@
+<?php
+
+class SessionMock {
+	protected $session;
+	public function has($key)
+	{
+		return isset($this->session[$key]);
+	}
+	public function get($key)
+	{
+		return $this->session[$key];
+	}
+	public function put($key, $value)
+	{
+		$this->session[$key] = $value;
+	}
+}