public class OptimizelyUserContext {  public var userId: String  public var attributes: [String: Any?]    public init(optimizely: OptimizelyClient,              userId: String,               attributes: [String: Any]? = nil)    // Set an attribute for the user.  public func setAttribute(key: String, value: Any) -> Bool        // Make a decision about which flag variation the user buckets into for the flag key.  public func decide(key: String,                      options: [OptimizelyDecideOption]? = nil) -> OptimizelyDecision    // Make decisions about which flag variations the user buckets into for flag keys.  public func decide(keys: [String],                                    options: [OptimizelyDecideOption]? = nil) -> [String: OptimizelyDecision]    // Make decisions about which flag variations the user buckets into for all flags.  public func decideAll(options: [OptimizelyDecideOption]? = nil) -> [String: OptimizelyDecision]    // Track user event.  public func trackEvent(eventKey: String, eventTags:  [String: Any]? = nil)    // OptimizelyDecisionContext  public struct OptimizelyDecisionContext {    public let flagKey: String    public let ruleKey: String?  }    // OptimizelyForcedDecision  public struct OptimizelyForcedDecision {    public let variationKey:String  }    // Sets a forced decision (variationKey) for a given decision context (flagKey and optional ruleKey).  public func setForcedDecision(context: OptimizelyDecisionContext,                                 decision: OptimizelyForcedDecision) -> Bool    // Returns the forced decision (variationKey) for a given decision context (flagKey and optional ruleKey).  public func getForcedDecision(context: OptimizelyDecisionContext) -> OptimizelyForcedDecision?  // Removes the forced decision (variationKey) for a given decision context (flagKey and optional ruleKey).  public func removeForcedDecision(context: OptimizelyDecisionContext) -> Bool  // Removes all the forced decisions (variationKeys) for the user context.  public func removeAllForcedDecisions() -> Bool  //  // The following methods require Real-Time Audiences for Feature Experimentation.   // See note following this code sample.   //  // An array of audience segment names that the user is qualified for.   // The result of **fetchQualifiedSegments()** is saved here.   // Can be nil if not properly updated with fetchQualifiedSegments().   //   //  You can read and write directly to the qualified segments array.   //  This lets you bypass the remote fetching process from ODP   //  or for utilizing your own fetching service.     public var qualifiedSegments: [String]?   // Fetch all qualified audience segments for the user context.   //  // The segments fetched are saved in **qualifiedSegments** and can be accessed any time.  // On failure, **qualifiedSegments** is nil and one of the following errors are returned:  // - OptimizelyError.invalidSegmentIdentifier  // - OptimizelyError.fetchSegmentsFailed(String)  //  // - Parameters:  //   - options – (Optional) A set of options for fetching qualified segments.  //   - completionHandler – A completion handler to be called with the fetch result.   //     On success, it passes a non-nil segments array (can be empty) with a nil error.   //     On failure, it passes a non-nil error with a nil segments array.  public func fetchQualifiedSegments(options: [OptimizelySegmentOption] = [],                                     completionHandler: @escaping ([String]?, OptimizelyError?) -> Void)  //  Check is the user qualified for the given segment.   // - Parameter segment – The segment name to check qualification for.  // - Returns – True, if qualified.  public func isQualifiedFor(segment: String) -> Bool}