Why detectron2 dont have epoch design ?

[lucasjinreal]

Epoch can easily knows how many epoch need to train, but iterations is coupled with batchsize, if you set batchsize less, you may need longer iterations.

I recently found a serious problem of this design:
it seems iterations can not fully see all images in training set, not like epochs iteration all dataset every single epoch, but iterations might make some samples not be trained at all.