code: def test_empty_spikes_plot(self):
      spikes = Spikes([], vdims=["Intensity"])
      plot = bokeh_renderer.get_plot(spikes)
      source = plot.handles["source"]
      self.assertEqual(len(source.data["x"]), 0)
      self.assertEqual(len(source.data["y0"]), 0)
      self.assertEqual(len(source.data["y1"]), 0)
  
imports: import datetime
  import numpy
  from bokeh.models import CategoricalColorMapper, LinearColorMapper
  from holoviews.core import NdOverlay
  from holoviews.element import Spikes
  from holoviews.plotting.bokeh.util import property_to_dict
  from ..utils import ParamLogStream
  from .test_plot import TestBokehPlot, bokeh_renderer
label_desc: Use image node_id 2 for calling the TestSpikesPlot obj's underlying member method code with example usage: obj.test_empty_spikes_plot() without return types