If the deserializeAsModel() method detects an error while deserializing
the model, it throws an AuthnErrorException. If the added validation checks
in validateSubmittedAttributes detect an error, they also throw this
exception.
The adapter should catch this exception and send an API error response using the method
AuthnApiSupport.writeErrorResponse().
try
{
...
}
catch (AuthnErrorException e)
{
// A validation error occurred while processing an API request, return an error response to the API client
apiSupport.writeErrorResponse(req, resp, e.getValidationError());
authnAdapterResponse.setAuthnStatus(AUTHN_STATUS.IN_PROGRESS);
return authnAdapterResponse;
}