briefly explain the role of ```_tranpose_and_gather_feat```?

[yezhengli-Mr9]

Possible to briefly explain the role of _tranpose_and_gather_feat(..) in models/py_utils/kp.py? I have to thoroughly understand this in order to understand role of exct_decode in ExtremeNet/models/py_utils/kp_utils.py as well as the role of _decode in CornerNet/models/py_utils/kp_utils.py?

Here I @xingyizhou just in case.

Sorry about this bothering,

I observe _tranpose_and_gather_feat(..) as a major difference between _train(...) and _test(...). To illustrate my this point ("major difference"), I merge the corresponding _train(...) and _test(...) in ExtremeNet/models/py_utils/exkp.py into my version of def forward(...).