code: def test_spikes_colormapping(self):
      spikes = Spikes(np.random.rand(20, 2), vdims=["Intensity"])
      color_spikes = spikes.opts(color_index=1)
      self._test_colormapping(color_spikes, 1)
  
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 1 for calling the TestSpikesPlot obj's underlying member method code with example usage: obj.test_spikes_colormapping() without return types