code: def setUp(self):
      self.pred_masks = np.zeros((1, 0, 2, 2), dtype=np.bool)
      self.pred_labels = np.zeros((1, 0), dtype=np.int32)
      self.pred_scores = np.zeros((1, 0), dtype=np.float32)
      self.gt_masks = np.array([[[[True, True], [True, True]]]])
      self.gt_labels = np.array([[1, 2]])
  
imports: import numpy
  import os
  from six.moves.urllib import request
  import unittest
  from chainer import testing
  from chainercv.evaluations import eval_instance_segmentation_coco
label_desc: Use image node_id 1 for calling the TestEvalInstanceSegmentationCOCOEmptyPred obj's underlying member method code with example usage: obj.setUp() without return types