code: def test_spikes_datetime_vdim_hover(self):
      points = Spikes(
          [(0, 1, dt.datetime(2017, 1, 1))], vdims=["value", "date"]
      ).opts(tools=["hover"])
      plot = bokeh_renderer.get_plot(points)
      cds = plot.handles["cds"]
      self.assertEqual(
          cds.data["date"].astype("datetime64"),
          np.array([1483228800000000000]),
      )
      hover = plot.handles["hover"]
      self.assertEqual(
          hover.tooltips,
          [
              ("x", "@{x}"),
              ("value", "@{value}"),
              ("date", "@{date}{%F %T}"),
          ],
      )
      self.assertEqual(hover.formatters, {"@{date}": "datetime"})
  
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 14 for calling the TestSpikesPlot obj's underlying member method code with example usage: obj.test_spikes_datetime_vdim_hover() without return types