--- /dev/null
+--TEST--
+Bug #20563 isMultipart() method tests
+--SKIPIF--
+--FILE--
+<?php
+include("Mail/mime.php");
+
+$mime = new Mail_mime;
+
+echo ($mime->isMultipart() ? 'TRUE' : 'FALSE') . "\n";
+
+$mime->setTXTBody('test');
+
+echo ($mime->isMultipart() ? 'TRUE' : 'FALSE') . "\n";
+
+$mime->setHTMLBody('test');
+
+echo ($mime->isMultipart() ? 'TRUE' : 'FALSE') . "\n";
+
+--EXPECT--
+FALSE
+FALSE
+TRUE