code: def accumulate(self):
      metrics = mm.metrics.motchallenge_metrics
      mh = mm.metrics.create()
      summary = self.MOTEvaluator.get_summary(
          self.accs, self.seqs, metrics
      )
      self.strsummary = mm.io.render_summary(
          summary,
          formatters=mh.formatters,
          namemap=mm.io.motchallenge_metric_names,
      )
      if self.save_summary:
          self.MOTEvaluator.save_summary(
              summary, os.path.join(self.result_root, "summary.xlsx")
          )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import copy
  import sys
  import math
  from collections import defaultdict
  import numpy
  from ppdet.modeling.bbox_utils import bbox_iou_np_expand
  from .map_utils import ap_per_class
  from .metrics import Metric
  from .munkres import Munkres
  from ppdet.utils.logger import setup_logger
label_desc: Use image node_id 4 for calling the MOTMetric obj's underlying member method code with example usage: obj.accumulate() without return types