FirebaseVisionFaceContour.ContourType Contour types for face. 
FirebaseVisionFaceDetectorOptions.ClassificationMode Indicates whether to run additional classifiers for characterizing attributes such as "smiling" and "eyes open". 
FirebaseVisionFaceDetectorOptions.ContourMode Sets whether to detect contours or not. 
FirebaseVisionFaceDetectorOptions.LandmarkMode Sets whether to detect no landmarks or all landmarks. 
FirebaseVisionFaceDetectorOptions.PerformanceMode Extended option for controlling additional accuracy / speed trade-offs in performing face detection. 
FirebaseVisionFaceLandmark.LandmarkType Landmark types for face.