code: def test_mark_groups_squares(self):
      g = Graph.Ring(5, directed=True)
      lo = g.layout("auto")
      plot(
          g,
          layout=lo,
          target=result_image_folder
          / "graph_mark_groups_squares_directed.png",
          backend="cairo",
          mark_groups=True,
          vertex_shape="square",
      )
  
imports: import random
  import unittest
  from igraph import Graph, plot, VertexClustering
label_desc: Use image node_id 6 for calling the GraphTestRunner obj's underlying member method code with example usage: obj.test_mark_groups_squares() without return types