code: def _reset_metrics(self):
      for metric in self._metrics:
          metric.reset()
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import glob
  import re
  import paddle
  import paddle.nn
  import numpy
  from tqdm import tqdm
  from collections import defaultdict
  from ppdet.core.workspace import create
  from ppdet.utils.checkpoint import load_weight, load_pretrain_weight
  from ppdet.modeling.mot.utils import Detection, get_crops, scale_coords, clip_box
  from ppdet.modeling.mot.utils import MOTTimer, load_det_results, write_mot_results, save_vis_results
  from ppdet.modeling.mot.tracker import JDETracker, CenterTracker
  from ppdet.modeling.mot.tracker import DeepSORTTracker, OCSORTTracker, BOTSORTTracker
  from ppdet.modeling.architectures import YOLOX
  from ppdet.metrics import Metric, MOTMetric, KITTIMOTMetric, MCMOTMetric
  from ppdet.data.source.category import get_categories
  import ppdet.utils.stats
  from .callbacks import Callback, ComposeCallback
  from ppdet.utils.logger import setup_logger
label_desc: Use image node_id 4 for calling the Tracker obj's underlying member method code with example usage: obj._reset_metrics() without return types