code: private function isHydraOperation(\ReflectionMethod $method)
      {
          $annotation = $this->annotationReader->getMethodAnnotation(
              $method,
              'ML\HydraBundle\Mapping\Operation'
          );
  
          return null !== $annotation;
      }
docs: Does the specified method represent a Hydra Operation?
  
  This information is used to determine whether it's return value
  should be serialized by the Hydra serializer.
  
  Currently annotations are the only way to specify a method to be a
  Hydra operation.
  
  @param \ReflectionMethod $method The controller method.
  
  @return boolean True if the method represents a Hydra Operation,
  false otherwise