A ControllerResolverInterface implementation knows how to determine the controller to execute based on a Request object.
A Controller can be any valid PHP callable.
at line 40
Returns the Controller instance associated with a Request.
As several resolvers can exist for a single application, a resolver must return false when it is not able to determine the controller.
The resolver must only throw an exception when it should be able to load controller but cannot because of some errors made by the developer.