code: def test_heatmap_invert_xaxis(self):
      hmap = HeatMap([("A", 1, 1), ("B", 2, 2)]).opts(invert_xaxis=True)
      plot = mpl_renderer.get_plot(hmap)
      array = plot.handles["artist"].get_array()
      if mpl38:
          expected = np.array([[1, np.inf], [np.inf, 2]])
      else:
          expected = np.array([1, np.inf, np.inf, 2])
      masked = np.ma.array(
          expected, mask=np.logical_not(np.isfinite(expected))
      )
      np.testing.assert_equal(array, masked)
  
file_path: holoviews/holoviews/tests/plotting/matplotlib/test_heatmapplot.py
imports: import numpy
  from holoviews.element import HeatMap, Image
  from .test_plot import TestMPLPlot, mpl38, mpl_renderer
label_desc: Use image node_id 3 for calling the TestHeatMapPlot obj's underlying member method code with example usage: obj.test_heatmap_invert_xaxis() without return types