'Alternate auth data on next request
Configure auth provider to provide alt authentication data
on a part of the *next* auth_request. If credentials are None,
set invalid data.
:param request_part: request part to contain invalid auth: url,
headers, body
:param auth_data: alternative auth_data from which to get the
invalid data to be injected'

def set_alt_auth_data(self, request_part, auth_data):

    self.alt_part = request_part
    self.alt_auth_data = auth_data
