public function testAlwaysGetSingleSender()
{
$message = new Message();
$message->setSender('*****@*****.**');
$this->assertEquals(['*****@*****.**' => null], $message->getSender(), "Simple email address as string does not work for setSender().");
$message->setSender(['*****@*****.**', '*****@*****.**']);
$this->assertEquals(['*****@*****.**' => null], $message->getSender(), "Only first of the two emails should have been set for setSender().");
$message->setSender(['*****@*****.**']);
$this->assertEquals(['*****@*****.**' => null], $message->getSender(), "Simple array with one email address should work with setSender().");
}
