code: def test_centroid_y(self):
      self.assertEqual(self.yc, (self.bottom + self.top) / 2.0)
  
imports: import unittest
  from holoviews.core import AARectangle, BoundingBox
label_desc: Use image node_id 8 for calling the TestBoundingBox obj's underlying member method code with example usage: obj.test_centroid_y() without return types