code: def test_cubehelix_against_matplotlib(self):
      x = np.linspace(0, 1, 8)
      mpl_pal = mpl.cm.cubehelix(x)[:, :3].tolist()
  
      sns_pal = palettes.cubehelix_palette(
          8, start=0.5, rot=-1.5, hue=1, dark=0, light=1, reverse=True
      )
  
      assert sns_pal == mpl_pal
  
imports: import colorsys
  import numpy
  import matplotlib
  import pytest
  import numpy.testing
  from seaborn import palettes, utils, rcmod
  from seaborn.external import husl
  from seaborn._compat import get_colormap
  from seaborn.colors import xkcd_rgb, crayons
label_desc: Use image node_id 27 for calling the TestColorPalettes obj's underlying member method code with example usage: obj.test_cubehelix_against_matplotlib() without return types