public function testConcat($registryArray = [], $collectionArray = [], $expectArray = [])
{
/* setup */
$optionArray = ['directory' => Stream::url('root/cache/styles'), 'extension' => 'css', 'attribute' => 'href', 'lifetime' => 86400];
$this->_registry->init($registryArray);
$loader = new Assetic\Loader($this->_registry);
$loader->init($collectionArray, 'css')->concat($optionArray)->concat($optionArray);
/* actual */
$actualArray = $loader->getCollectionArray();
/* compare */
$this->assertEquals($expectArray, $actualArray);
}