FaceLandmarkerLiveStreamDelegate
protocol FaceLandmarkerLiveStreamDelegate : NSObjectProtocolThis protocol defines an interface for the delegates of FaceLandmarker face to receive
 results of performing asynchronous face detection on images (i.e, when runningMode =
 .liveStream).
The delegate of FaceLandmarker must adopt FaceLandmarkerLiveStreamDelegate protocol.
 The methods in this protocol are optional.
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                  This method notifies a delegate that the results of asynchronous face detection of an image submitted to the FaceLandmarkeris available.This method is called on a private serial dispatch queue created by the FaceLandmarkerfor performing the asynchronous delegates calls.DeclarationSwift func faceLandmarker(_ faceLandmarker: MPPFaceLandmarker, didFinishDetection result: FaceLandmarkerResult?, timestampInMilliseconds: Int, error: Error?)ParametersfaceLandmarkerThe face landmarker which performed the face landmark detctions. This is useful to test equality when there are multiple instances of FaceLandmarker.resultThe FaceLandmarkerResultobject that contains a list of landmarks.timestampInMillisecondsThe timestamp (in milliseconds) which indicates when the input image was sent to the face detector. errorAn optional error parameter populated when there is an error in performing face detection on the input live stream image data.