code: def test_data_compositor_definition(self):
      definition = " data transform(Image * Image) HCSTEST"
      self.line_magic("compositor", definition)
  
      compositors = [
          c for c in Compositor.definitions if c.group == "HCSTEST"
      ]
      self.assertEqual(len(compositors), 1)
      self.assertEqual(compositors[0].group, "HCSTEST")
      self.assertEqual(compositors[0].mode, "data")
  
imports: from unittest import SkipTest
  import holoviews
  from holoviews.core.options import Store
  from pyviz_comms import CommManager
  from holoviews.operation import Compositor
label_desc: Use image node_id 4 for calling the TestCompositorMagic obj's underlying member method code with example usage: obj.test_data_compositor_definition() without return types