code: def test_unconnected_graphs_betweenness_centrality(centrality_func):
      G = nx.Graph([(1, 2), (3, 4)])
      G.add_node(5)
      with pytest.raises(nx.NetworkXError, match="Graph not connected"):
          centrality_func(G)
  
imports: import pytest
  import networkx
  from networkx import approximate_current_flow_betweenness_centrality
  from networkx import edge_current_flow_betweenness_centrality
label_desc: Use image node_id 1 for calling a global function with example usage: test_unconnected_graphs_betweenness_centrality(centrality_func) without return types