code: def test_hline_styling(self):
      self.assert_shape_element_styling(HLine(3))
  
imports: import numpy
  from holoviews.element import Bounds, Box, HLine, Path, Rectangles, Segments, Tiles, VLine
  from .test_plot import TestPlotlyPlot
label_desc: Use image node_id 8 for calling the TestVLineHLine obj's underlying member method code with example usage: obj.test_hline_styling() without return types