class_docstr: Smoke tests for the Python examples found on the homepage to ensure
  that they do not break.
code: def testMSTofGRG(self):
      def distance(p1, p2):
          return ((p1[0] - p2[0]) ** 2 + (p1[1] - p2[1]) ** 2) ** 0.5
  
      g = Graph.GRG(100, 0.2)
      layout = Layout(list(zip(g.vs["x"], g.vs["y"])))
  
      weights = [
          distance(layout[edge.source], layout[edge.target])
          for edge in g.es
      ]
      max_weight = max(weights)
      g.es["width"] = [
          6 - 5 * weight / max_weight for weight in weights
      ]
      g.spanning_tree(weights)
  
file_path: python-igraph/tests/test_homepage.py
imports: import unittest
  from igraph import Graph, Layout
label_desc: Use image node_id 3 for calling the HomepageExampleTests obj's underlying member method code with example usage: obj.testMSTofGRG() and returns: unknown