class OptimizelyUserContext implements \JsonSerializable{    // Create an instance of the Optimizely User Context. Pass in user id and optionally user attributes     public function __construct(Optimizely $optimizelyClient, $userId, array $attributes = [], $forcedDecisions = null);        // get user id for the user    public function getUserId();    // set user attributes    public function setAttribute($key, $value);      // get user attributes    public function getAttributes();    // make a decision about which flag variation the user buckets into for the flag key    public function decide($key, array $options = []);    // make decisions about which flag variations the user buckets into for flag keys     public function decideForKeys(array $keys, array $options = []);    // make decisions about which flag variations the user buckets into for all flags     public function decideAll(array $options = []);    // track user event    public function trackEvent($eventKey, array $eventTags = []);        // Sets the forced decision (variationKey) for a given decision context    public function setForcedDecision($context, $decision);    // Returns the forced decision for a given decision context    public function getForcedDecision($context);    // Removes the forced decision for a given decision context    public function removeForcedDecision($context);    // Removes all forced decisions bound to this user context    public function removeAllForcedDecisions();}