code: def test_raster_ellipsis_slice_value(self):
      data = np.random.rand(10, 10)
      sliced = hv.Raster(data)[..., "z"]
      self.assertEqual(sliced.data, data)
  
imports: import numpy
  import holoviews
  from holoviews.element.comparison import ComparisonTestCase
label_desc: Use image node_id 1 for calling the TestEllipsisRaster obj's underlying member method code with example usage: obj.test_raster_ellipsis_slice_value() without return types