--- /dev/null
+<?php
+
+/*
+ * This file is part of the Behat Testwork.
+ * (c) Konstantin Kudryashov <ever.zet@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Behat\Testwork\Call\Filter;
+
+use Behat\Testwork\Call\CallCenter;
+use Behat\Testwork\Call\CallResult;
+
+/**
+ * Filters call results and produces new ones.
+ *
+ * @see CallCenter
+ *
+ * @author Konstantin Kudryashov <ever.zet@gmail.com>
+ */
+interface ResultFilter
+{
+ /**
+ * Checks if filter supports call result.
+ *
+ * @param CallResult $result
+ *
+ * @return Boolean
+ */
+ public function supportsResult(CallResult $result);
+
+ /**
+ * Filters call result and returns a new result.
+ *
+ * @param CallResult $result
+ *
+ * @return CallResult
+ */
+ public function filterResult(CallResult $result);
+}