code: def test_rgb_to_hsl_part_13():
      """Test rgb to hsl color function"""
      assert rgb_to_hsl(0, 0, 0) == (0, 0, 0)
      assert rgb_to_hsl(51, 0, 0) == (0, 100, 10)
      assert rgb_to_hsl(102, 0, 0) == (0, 100, 20)
      assert rgb_to_hsl(153, 0, 0) == (0, 100, 30)
      assert rgb_to_hsl(204, 0, 0) == (0, 100, 40)
      assert rgb_to_hsl(255, 0, 0) == (0, 100, 50)
      assert rgb_to_hsl(255, 51, 51) == (0, 100, 60)
      assert rgb_to_hsl(255, 102, 102) == (0, 100, 70)
      assert rgb_to_hsl(255, 153, 153) == (0, 100, 80)
      assert rgb_to_hsl(255, 204, 204) == (0, 100, 90)
      assert rgb_to_hsl(255, 255, 255) == (0, 0, 100)
  
imports: from __future__ import division
  from pygal.colors import darken, desaturate, hsl_to_rgb, lighten, parse_color, rgb_to_hsl, rotate, saturate, unparse_color
label_desc: Use image node_id 35 for calling a global function with example usage: test_rgb_to_hsl_part_13() without return types