code: def setUp(self):
      self.prec = [
          np.array(prec_l) if prec_l is not None else None
          for prec_l in self.prec
      ]
      self.rec = [
          np.array(rec_l) if rec_l is not None else None
          for rec_l in self.rec
      ]
  
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 TestCalcDetectionVOCAP obj's underlying member method code with example usage: obj.setUp() without return types