Checks if the input data can be handled by this class. Throws an error if it can't handle the data.
Input data that would be handled potentially.
A promise resolving if this input can be handled, rejecting with an Error if not.
The data to handle.
The result of the handle function of the handler.
Extracts preferences from the Accept-* headers from an incoming HttpRequest. Supports Accept, Accept-Charset, Accept-Encoding, Accept-Language and Accept-DateTime.