code: def test_traverse_derived_streams(self):
      from holoviews.tests.test_streams import Val
  
      decollated = self.dmap_derived.decollate()
  
      # Check decollated types
      self.assertIsInstance(decollated, DynamicMap)
      self.assertEqual(len(decollated.streams), 3)
      for stream in decollated.streams:
          self.assertIsInstance(stream, Val)
  
      # Compute expected result
      expected = self.dmap_derived.callback.callable(6.0)
      decollated.streams[0].event(v=1.0)
      decollated.streams[1].event(v=2.0)
      decollated.streams[2].event(v=3.0)
      result = decollated[()]
  
      self.assertEqual(expected, result)
  
imports: from unittest import skipIf
  import param
  from holoviews.core import DynamicMap, GridSpace, HoloMap, NdOverlay, Overlay
  from holoviews.element import Points
  from holoviews.element.comparison import ComparisonTestCase
  from holoviews.streams import PlotSize, RangeXY, Stream
label_desc: Use image node_id 17 for calling the TestDecollation obj's underlying member method code with example usage: obj.test_traverse_derived_streams() without return types