code: def test_not_fulfilling_euler_formula(self):
      embedding = nx.PlanarEmbedding()
      for i in range(5):
          ref = None
          for j in range(5):
              if i != j:
                  embedding.add_half_edge(i, j, cw=ref)
                  ref = j
      with pytest.raises(nx.NetworkXException):
          embedding.check_structure()
  
imports: import pytest
  import networkx
  from networkx.algorithms.planarity import check_planarity_recursive, get_counterexample, get_counterexample_recursive
label_desc: Use image node_id 7 for calling the TestPlanarEmbeddingClass obj's underlying member method code with example usage: obj.test_not_fulfilling_euler_formula() without return types