requestCreator property
Function used to create a Request object for each HTTP request.
Applications can set this to a RequestCreator function that returns a subclass of Request or a Future that produces one. This allows them to pass custom information to handlers in the request object and to perform custom cleanup at the end of request processing (by overriding the the Request.release method).
If this is not set by the application, the default simply creates a Request object.
Implementation
RequestCreator requestCreator = _defaultRequestCreator;