what does kNumGatherPointFeature mean? What's my kNumGatherPointFeature，and my RPN_HEAD_CFGS as show blow:

[qiuhui1991]

RPN_HEAD_CFGS: [
{
'HEAD_CLS_NAME': [ 'vehicle' ],
},
{
'HEAD_CLS_NAME': [ 'car' ],
},
{
'HEAD_CLS_NAME': [ 'pedestrian'],
},
{
'HEAD_CLS_NAME': [ 'cyclist' ],
},
]