code: def test_class_init_with_data_string(self):
      self.G = UndirectedGraph([("a", "b"), ("b", "c")])
      self.assertListEqual(sorted(self.G.nodes()), ["a", "b", "c"])
      self.assertListEqual(
          hf.recursive_sorted(self.G.edges()), [["a", "b"], ["b", "c"]]
      )
  
imports: from pgmpy.base import UndirectedGraph
  from pgmpy.tests import help_functions
  import unittest
label_desc: Use image node_id 3 for calling the TestUndirectedGraphCreation obj's underlying member method code with example usage: obj.test_class_init_with_data_string() without return types