code: def test_same_max_and_relative_values_sparktext():
      """Test flat sparktexts"""
      chart = Line()
      chart.add("_", [0, 0, 0, 0, 0])
      assert chart.render_sparktext() == "▁▁▁▁▁"
  
      chart2 = Line()
      chart2.add("_", [1, 1, 1, 1, 1])
      assert chart2.render_sparktext(relative_to=1) == "▁▁▁▁▁"
  
file_path: pygal/pygal/test/test_sparktext.py
imports: from pygal import Bar, Line
label_desc: Use image node_id 7 for calling a global function with example usage: test_same_max_and_relative_values_sparktext() without return types