Add Composer autoloading functions and PHPStan for testing

vendor/symfony/console/Output/ConsoleOutputInterface.php

@@ -0,0 +1,32 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Console\Output;
+
+/**
+ * ConsoleOutputInterface is the interface implemented by ConsoleOutput class.
+ * This adds information about stderr and section output stream.
+ *
+ * @author Dariusz Górecki <darek.krk@gmail.com>
+ *
+ * @method ConsoleSectionOutput section() Creates a new output section
+ */
+interface ConsoleOutputInterface extends OutputInterface
+{
+    /**
+     * Gets the OutputInterface for errors.
+     *
+     * @return OutputInterface
+     */
+    public function getErrorOutput();
+
+    public function setErrorOutput(OutputInterface $error);
+}