code: def test_subgraph_copy(self):
      for origG in self.graphs:
          G = nx.Graph(origG)
          SG = G.subgraph([4, 5, 6])
          H = SG.copy()
          assert type(G) == type(H)
  
imports: import pytest
  import networkx
  from networkx.utils import edges_equal, nodes_equal
label_desc: Use image node_id 5 for calling the TestChainsOfViews obj's underlying member method code with example usage: obj.test_subgraph_copy() without return types