Visitor ID refers to the user's unique identifier (_visitor_id) after installing and before logging in.

       We provide an interface for developers to customize visitor IDs. If you have your own visitor management system and need to replace SolarEngine's visitor IDs, you should set it before initializing the SDK.

       During data reporting, only the latest visitor ID passed in will be used. Multiple calls should be avoided to prevent abnormal situations where multiple visitor IDs are reported consecutively.

Set Visitor ID

       Call setVisitorID: to set the visitor ID:

[[SolarEngineSDK sharedInstance] setVisitorID:@"vid8709901241"];

       This call only reports visitor IDs to the SDK and does not report _appLogin events.

Get Visitor ID

     Call getVisitorId to get the current visitor ID:

NSString *visitorId = [[SolarEngineSDK sharedInstance] visitorID];