/**
* @param $entityname
* @return BaseTransformer
* @throws \Exception
*/
public function getTransformer($entityname = null)
{
if (!$this->transformer || $entityname !== null && $this->transformer->getCurrentResourceKey() !== $entityname) {
if (null === $entityname) {
throw new \Exception('transformer is empty, specify the entity name into the parameter');
}
$this->transformer = $this->transformerResolver->resolve($entityname);
}
return $this->transformer;
}
