|Create a credentials object from the given response.
|Generate a new challenge to be sent to a client.
str giving the name of the authentication scheme with which this factory is associated. For example, 'basic' or 'digest'.
Create a credentials object from the given response.
|scheme specific response string
|The request being processed (from which the response was taken).
|The credentials represented by the given response.
|If the response is invalid.