questions about batch size and number of unet runs in the image generator task

[AndreaChiChengdu]

@PaulTR
Great project, I can already run it on my phone, but I have some questions, I want to understand the whole process of running pipline

1. Is unet batch=2 or batch=1?
2. if iterations=20, unet is run 20 times in batch=2 or 40 times batch=1 or 20 times batch=1 ?
   3.I can't see about negative prompt in kotlin code or api?
   thanks