Update to drupal 8.0.0-rc1. For more information, see https://www.drupal.org/node/2582663

vendor/symfony/console/Event/ConsoleCommandEvent.php

@@ -0,0 +1,62 @@
+<?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\Event;
+
+/**
+ * Allows to do things before the command is executed, like skipping the command or changing the input.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class ConsoleCommandEvent extends ConsoleEvent
+{
+    /**
+     * The return code for skipped commands, this will also be passed into the terminate event.
+     */
+    const RETURN_CODE_DISABLED = 113;
+
+    /**
+     * Indicates if the command should be run or skipped.
+     *
+     * @var bool
+     */
+    private $commandShouldRun = true;
+
+    /**
+     * Disables the command, so it won't be run.
+     *
+     * @return bool
+     */
+    public function disableCommand()
+    {
+        return $this->commandShouldRun = false;
+    }
+
+    /**
+     * Enables the command.
+     *
+     * @return bool
+     */
+    public function enableCommand()
+    {
+        return $this->commandShouldRun = true;
+    }
+
+    /**
+     * Returns true if the command is runnable, false otherwise.
+     *
+     * @return bool
+     */
+    public function commandShouldRun()
+    {
+        return $this->commandShouldRun;
+    }
+}