Fix various compatibility issues with PHP 8

libs/swiftmailer/classes/Swift/Mailer/RecipientIterator.php

@@ -0,0 +1,32 @@
+<?php
+
+/*
+ * This file is part of SwiftMailer.
+ * (c) 2004-2009 Chris Corbyn
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+/**
+ * Provides an abstract way of specifying recipients for batch sending.
+ *
+ * @author Chris Corbyn
+ */
+interface Swift_Mailer_RecipientIterator
+{
+    /**
+     * Returns true only if there are more recipients to send to.
+     *
+     * @return bool
+     */
+    public function hasNext();
+
+    /**
+     * Returns an array where the keys are the addresses of recipients and the
+     * values are the names. e.g. ('foo@bar' => 'Foo') or ('foo@bar' => NULL).
+     *
+     * @return array
+     */
+    public function nextRecipient();
+}