code: def next_id():
      BaseTrack._count += 1
      return BaseTrack._count
  
imports: import numpy
  from collections import deque, OrderedDict
  from ..matching import jde_matching
  from ppdet.core.workspace import register, serializable
label_desc: Use image node_id 2 for calling the BaseTrack obj's underlying member method code with example usage: obj.next_id() and returns: BaseTrack