how to EvalHook by_epoch=False

[Chop1]

How to perform evaluation multiple time per epoch ?
In other mmlab codebase, we case specify in evaluation form the config file, by_epoch=False and set interval=500 to evaluate every 500 iterations.
But mmdetection implement another version of evalHook, which dont seems to support this features. Is it possible ?

[Chop1]

So in fact mmdetection train API override the passed parameters by_epoch

mmdetection/mmdet/apis/train.py

Line 227 in e71b499

eval_cfg['by_epoch'] = cfg.runner['type'] != 'IterBasedRunner'

is this line needed to prevent some bad behaviour ?