default List<Credential> fromAuthentication(final HttpServletRequest request,
                                                final MultiValueMap<String, String> requestBody,
                                                final Authentication authentication,
                                                final MultifactorAuthenticationProvider provider) {
        return new ArrayList<>();
    }
From authentication.

@param request        the request
@param requestBody    the request body
@param authentication the authn
@param provider       the provider
@return the list
core/cas-server-core-rest-api/src/main/java/org/apereo/cas/rest/factory/RestHttpRequestCredentialFactory.java