code: def test_zero_and_non_zero_entries(self):
      y_pred = np.array([1], dtype=np.float32)
      y_true = np.array([1])
  
      obj = metrics.IoU(num_classes=2, target_class_ids=[0, 1])
      result = obj(y_true, y_pred)
  
      # cm = [[0, 0],
      #       [0, 1]]
      # sum_row = [0, 1], sum_col = [0, 1], true_positives = [0, 1]
      # iou = true_positives / (sum_row + sum_col - true_positives))
      expected_result = (1 / (1 + 1 - 1)) / 1
      self.assertAllClose(result, expected_result, atol=1e-3)
  
imports: import numpy
  import pytest
  from keras import layers
  from keras import models
  from keras import testing
  from keras.metrics import iou_metrics
label_desc: Use image node_id 6 for calling the IoUTest obj's underlying member method code with example usage: obj.test_zero_and_non_zero_entries() without return types