code: def test_basic_sparktext():
      """Test basic sparktext"""
      chart = Line()
      chart.add("_", [1, 5, 22, 13, 53])
      assert chart.render_sparktext() == "▁▁▃▂█"
  
file_path: pygal/pygal/test/test_sparktext.py
imports: from pygal import Bar, Line
label_desc: Use image node_id 1 for calling a global function with example usage: test_basic_sparktext() without return types