code: def test_spikes_line_width_op(self):
      spikes = Spikes(
          [(0, 0, 1), (0, 1, 4), (0, 2, 8)], vdims=["y", "line_width"]
      ).opts(linewidth="line_width")
      plot = mpl_renderer.get_plot(spikes)
      artist = plot.handles["artist"]
      self.assertEqual(artist.get_linewidths(), [1, 4, 8])
  
imports: import numpy
  import pytest
  from holoviews.core.options import AbbreviatedException
  from holoviews.core.overlay import NdOverlay
  from holoviews.core.spaces import HoloMap
  from holoviews.element import Spikes
  from ..utils import ParamLogStream
  from .test_plot import TestMPLPlot, mpl_renderer
label_desc: Use image node_id 17 for calling the TestSpikesPlot obj's underlying member method code with example usage: obj.test_spikes_line_width_op() without return types