--- /dev/null
+<?php
+
+/*
+ * This file is part of the Prophecy.
+ * (c) Konstantin Kudryashov <ever.zet@gmail.com>
+ * Marcello Duarte <marcello.duarte@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Prophecy\Doubler;
+
+/**
+ * Core double interface.
+ * All doubled classes will implement this one.
+ *
+ * @author Konstantin Kudryashov <ever.zet@gmail.com>
+ */
+interface DoubleInterface
+{
+}