code: def test_dynamic_subplot_creation(self):
      def cb(X):
          return NdOverlay(
              {i: Curve(np.arange(10) + i) for i in range(X)}
          )
  
      dmap = DynamicMap(cb, kdims=["X"]).redim.range(X=(1, 10))
      plot = mpl_renderer.get_plot(dmap)
      self.assertEqual(len(plot.subplots), 1)
      plot.update((3,))
      self.assertEqual(len(plot.subplots), 3)
      for i, subplot in enumerate(plot.subplots.values()):
          self.assertEqual(subplot.cyclic_index, i)
  
imports: import numpy
  from holoviews.core import DynamicMap, HoloMap, NdOverlay, Overlay
  from holoviews.element import Curve, Scatter
  from ...utils import LoggingComparisonTestCase
  from .test_plot import TestMPLPlot, mpl_renderer
label_desc: Use image node_id 8 for calling the TestOverlayPlot obj's underlying member method code with example usage: obj.test_dynamic_subplot_creation() and returns: NdOverlay