code: def test_to_numpy_array_structured_multigraph_raises(graph_type):
      G = nx.path_graph(3, create_using=graph_type)
      dtype = np.dtype([("weight", int), ("cost", int)])
      with pytest.raises(
          nx.NetworkXError, match="Structured arrays are not supported"
      ):
          nx.to_numpy_array(G, dtype=dtype, weight=None)
  
imports: import pytest
  import networkx
  from networkx.generators.classic import barbell_graph, cycle_graph, path_graph
  from networkx.utils import graphs_equal
label_desc: Use image node_id 14 for calling a global function with example usage: test_to_numpy_array_structured_multigraph_raises(graph_type) without return types