9 files declare their use of PromiseInterface in Auth0 Single Sign On 8.2

ClientInterface.php in vendor/guzzlehttp/guzzle/src/ClientInterface.php

HandlerStack.php in vendor/guzzlehttp/guzzle/src/HandlerStack.php

MockHandler.php in vendor/guzzlehttp/guzzle/src/Handler/MockHandler.php

Pool.php in vendor/guzzlehttp/guzzle/src/Pool.php

PrepareBodyMiddleware.php in vendor/guzzlehttp/guzzle/src/PrepareBodyMiddleware.php

RedirectMiddleware.php in vendor/guzzlehttp/guzzle/src/RedirectMiddleware.php

RequestException.php in vendor/guzzlehttp/guzzle/src/Exception/RequestException.php

RetryMiddleware.php in vendor/guzzlehttp/guzzle/src/RetryMiddleware.php

StreamHandler.php in vendor/guzzlehttp/guzzle/src/Handler/StreamHandler.php