code: def setUp(self):
      self.pred_bboxes = (np.array(bbox) for bbox in self.pred_bboxes)
      self.pred_labels = (np.array(label) for label in self.pred_labels)
      self.pred_scores = (np.array(score) for score in self.pred_scores)
      self.gt_bboxes = (np.array(bbox) for bbox in self.gt_bboxes)
      self.gt_labels = (np.array(label) for label in self.gt_labels)
  
      if hasattr(self, "gt_difficults"):
          self.gt_difficults = (
              np.array(difficult) for difficult in self.gt_difficults
          )
      else:
          self.gt_difficults = None
  
imports: from __future__ import division
  import numpy
  import os
  from six.moves.urllib import request
  import unittest
  from chainer import testing
  from chainercv.evaluations import calc_detection_voc_ap
  from chainercv.evaluations import calc_detection_voc_prec_rec
  from chainercv.evaluations import eval_detection_voc
label_desc: Use image node_id 1 for calling the TestCalcDetectionVOCPrecRec obj's underlying member method code with example usage: obj.setUp() without return types