--- /dev/null
+<?php
+namespace Robo\Contract;
+
+/**
+ * Any Robo tasks that implements this interface will
+ * be called when the task collection it is added to
+ * completes.
+ *
+ * Interface CompletionInterface
+ * @package Robo\Contract
+ */
+interface CompletionInterface extends TaskInterface
+{
+ /**
+ * Revert an operation that can be rolled back
+ */
+ public function complete();
+}