class_docstr: CenterTrack network, see http://arxiv.org/abs/2004.01177
  
  Args:
      detector (object): 'CenterNet' instance
      plugin_head (object): 'CenterTrackHead' instance
      tracker (object): 'CenterTracker' instance
class_docstr_tok: ["CenterTrack","network",",","see","http",":","\/\/arxiv.org\/abs\/2004.01177","Args",":","detector","(","object",")",":","'CenterNet","'","instance","plugin_head","(","object",")",":","'CenterTrackHead","'","instance","tracker","(","object",")",":","'CenterTracker","'","instance"]
code: def from_config(cls, cfg, *args, **kwargs):
      detector = create(cfg["detector"])
      detector_out_shape = (
          detector.neck
          and detector.neck.out_shape
          or detector.backbone.out_shape
      )
  
      kwargs = {"input_shape": detector_out_shape}
      plugin_head = create(cfg["plugin_head"], **kwargs)
      tracker = create(cfg["tracker"])
  
      return {
          "detector": detector,
          "plugin_head": plugin_head,
          "tracker": tracker,
      }
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import copy
  import math
  import numpy
  import paddle
  from ppdet.core.workspace import register, create
  from .meta_arch import BaseArch
  from ..keypoint_utils import affine_transform
  from ppdet.data.transform.op_helper import gaussian_radius, gaussian2D, draw_umich_gaussian
label_desc: Use image node_id 2 for calling the CenterTrack obj's underlying member method code with example usage: obj.from_config(cls, cfg) and returns: dict