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.
@api
Request $request A Request instance:
mixed|Boolean A PHP callable representing the Controller, or false if this resolver is not able to determine the controller
\InvalidArgumentException|\LogicException If the controller can't be found
public function getController(Request $request);