code: def test_eigenvectors(self):
      np = pytest.importorskip("numpy")
      eigenval = np.linalg.eigvals
      pytest.importorskip("scipy")
  
      cs = "ddiiddid"
      G = nxt.threshold_graph(cs)
      (tgeval, tgevec) = nxt.eigenvectors(cs)
      np.testing.assert_allclose(
          [np.dot(lv, lv) for lv in tgevec], 1.0, rtol=1e-9
      )
      lapl = nx.laplacian_matrix(G)
  
imports: import pytest
  import networkx
  import networkx.algorithms.threshold
  from networkx.algorithms.isomorphism.isomorph import graph_could_be_isomorphic
label_desc: Use image node_id 17 for calling the TestGeneratorThreshold obj's underlying member method code with example usage: obj.test_eigenvectors() without return types