Add ProcessorInterface, an optional one to allow labelling Monolog processors

src/Monolog/Processor/ProcessorInterface.php

@@ -0,0 +1,25 @@
+<?php
+
+/*
+ * This file is part of the Monolog package.
+ *
+ * (c) Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Monolog\Processor;
+
+/**
+ * An optional interface to allow labelling Monolog processors.
+ *
+ * @author Nicolas Grekas <p@tchwork.com>
+ */
+interface ProcessorInterface
+{
+    /**
+     * @return array The processed records
+     */
+    public function __invoke(array $records);
+}