public function testAddingAndRemovingMultiHeaders()
{
$listener = new MergeHttpHeadersListener($this->mockContaoFramework());
$this->assertEquals($listener->getMultiHeaders(), ['set-cookie', 'link', 'vary', 'pragma', 'cache-control']);
$listener->removeMultiHeader('cache-control');
$this->assertEquals($listener->getMultiHeaders(), ['set-cookie', 'link', 'vary', 'pragma']);
$listener->addMultiHeader('dummy');
$this->assertEquals($listener->getMultiHeaders(), ['set-cookie', 'link', 'vary', 'pragma', 'dummy']);
$listener->setMultiHeader(['set-cookie', 'link', 'vary', 'pragma', 'cache-control']);
$this->assertEquals($listener->getMultiHeaders(), ['set-cookie', 'link', 'vary', 'pragma', 'cache-control']);
}