code: def testGreedyVertexColoring(self):
      g = Graph.Famous("petersen")
  
      col = g.vertex_coloring_greedy()
      assert_valid_vertex_coloring(g, col)
  
      col = g.vertex_coloring_greedy("colored_neighbors")
      assert_valid_vertex_coloring(g, col)
  
      col = g.vertex_coloring_greedy("dsatur")
      assert_valid_vertex_coloring(g, col)
  
imports: import unittest
  from igraph import Graph
label_desc: Use image node_id 1 for calling the VertexColoringTests obj's underlying member method code with example usage: obj.testGreedyVertexColoring() without return types