code: def test_hex_tiles_only_nans(self):
      tiles = HexTiles([(np.nan, 0), (1, np.nan)])
      plot = bokeh_renderer.get_plot(tiles)
      self.assertEqual(plot.handles["source"].data, {"q": [], "r": []})
  
imports: import numpy
  from holoviews.core import Dimension
  from holoviews.element import HexTiles
  from holoviews.plotting.bokeh.hex_tiles import hex_binning
  from holoviews.plotting.bokeh.util import property_to_dict
  from .test_plot import TestBokehPlot, bokeh_renderer
label_desc: Use image node_id 2 for calling the TestHexTilesPlot obj's underlying member method code with example usage: obj.test_hex_tiles_only_nans() without return types