code: def test_katz_centrality_toy(graph_file):
      # This test is based off of libcugraph_c and pylibcugraph tests
      G = graph_file.get_graph(
          create_using=cugraph.Graph(directed=True), download=True
      )
      alpha = 0.01
      beta = 1.0
      tol = 0.000001
      max_iter = 1000
      centralities = [
          0.410614,
          0.403211,
          0.390689,
          0.415175,
          0.395125,
          0.433226,
      ]
  
      ck = cugraph.katz_centrality(
          G, alpha=alpha, beta=beta, tol=tol, max_iter=max_iter
      )
  
      ck = ck.sort_values("vertex")
      for vertex in ck["vertex"].to_pandas():
          expected_score = centralities[vertex]
          actual_score = ck["katz_centrality"].iloc[vertex]
          assert (
              pytest.approx(expected_score, abs=1e-2) == actual_score
          ), (
              f"Katz centrality score is {actual_score}, should have"
              f"been {expected_score}"
          )
  
file_path: cugraph/python/cugraph/cugraph/tests/centrality/test_katz_centrality.py
imports: import gc
  import pytest
  import networkx
  import cudf
  import cugraph
  from cugraph.testing import utils, DEFAULT_DATASETS, UNDIRECTED_DATASETS
  from cugraph.datasets import toy_graph_undirected, karate
label_desc: Use image node_id 7 for calling a global function with example usage: test_katz_centrality_toy(graph_file) without return types