code: def test_op_ndoverlay_value(self):
      markers = ["d", "s"]
      overlay = NdOverlay(
          {
              marker: Points(np.arange(i))
              for i, marker in enumerate(markers)
          },
          "Marker",
      ).opts("Points", marker="Marker")
      plot = mpl_renderer.get_plot(overlay)
      for subplot, marker in zip(plot.subplots.values(), markers):
          style = dict(subplot.style[subplot.cyclic_index])
          style = subplot._apply_transforms(
              subplot.current_frame, {}, style
          )
          self.assertEqual(style["marker"], marker)
  
imports: import matplotlib.pyplot
  import numpy
  import pytest
  from holoviews.core.options import AbbreviatedException
  from holoviews.core.overlay import NdOverlay
  from holoviews.core.spaces import HoloMap
  from holoviews.element import Points
  from ..utils import ParamLogStream
  from .test_plot import TestMPLPlot, mpl_renderer
label_desc: Use image node_id 35 for calling the TestPointPlot obj's underlying member method code with example usage: obj.test_op_ndoverlay_value() without return types