Update

src/Composer/Plugin.php

@@ -37,6 +37,32 @@ class Plugin implements PluginInterface, EventSubscriberInterface
         $this->io = $io;
     }
 
+    /**
+     * Remove any hooks from Composer.
+     *
+     * This will be called when a plugin is deactivated before being
+     * uninstalled, but also before it gets upgraded to a new version
+     * so the old one can be deactivated and the new one activated.
+     *
+     * @param Composer    $composer
+     * @param IOInterface $io
+     */
+    public function deactivate(Composer $composer, IOInterface $io)
+    {
+    }
+
+    /**
+     * Prepare the plugin to be uninstalled.
+     *
+     * This will be called after deactivate.
+     *
+     * @param Composer    $composer
+     * @param IOInterface $io
+     */
+    public function uninstall(Composer $composer, IOInterface $io)
+    {
+    }
+
     /**
      * {@inheritdoc}
      */
@@ -52,7 +78,7 @@ class Plugin implements PluginInterface, EventSubscriberInterface
 
     public function onInstall(PackageEvent $event): void
     {
-        var_dumP($event);
+        \var_dumP($event);
     }
 
     /**