Executors.newSingleThreadExecutor() is never used

[AlexTrotsenko]

camera-samples/CameraX-MLKit/app/src/main/java/com/example/camerax_mlkit/MainActivity.kt

Line 58 in de8b235

cameraExecutor = Executors.newSingleThreadExecutor()

I see, that Executors.newSingleThreadExecutor() was added in the dcaf84f by @donovanfm, but it's never used.

Was there an idea to use it instead of ContextCompat.getMainExecutor(this) ? If so - what's the pros/cons of such single thread executor ?