code: def test_collate_gridspace_ndoverlay(self):
      grid = (
          self.nesting_hmap.groupby(["delta"])
          .collate(NdOverlay)
          .grid(["alpha", "beta"])
      )
      self.assertEqual(grid.dimensions(), self.nested_grid.dimensions())
      self.assertEqual(grid.keys(), self.nested_grid.keys())
      self.assertEqual(repr(grid), repr(self.nested_grid))
  
file_path: holoviews/holoviews/tests/core/test_collation.py
imports: import itertools
  import numpy
  from holoviews.core import Collator, GridSpace, HoloMap, NdOverlay, Overlay
  from holoviews.element import Curve
  from holoviews.element.comparison import ComparisonTestCase
label_desc: Use image node_id 4 for calling the TestCollation obj's underlying member method code with example usage: obj.test_collate_gridspace_ndoverlay() without return types