class_docstr: Unit tests for the :func:`~networkx.edge_boundary` function.
class_docstr_tok: ["Unit","tests","for","the",":","func",":","`","~networkx.edge_boundary","`","function","."]
code: def test_path_graph(self):
      P10 = cnlti(nx.path_graph(10), first_label=1)
      assert list(nx.edge_boundary(P10, [])) == []
      assert list(nx.edge_boundary(P10, [], [])) == []
      assert list(nx.edge_boundary(P10, [1, 2, 3])) == [(3, 4)]
      assert sorted(nx.edge_boundary(P10, [4, 5, 6])) == [
          (4, 3),
          (6, 7),
      ]
      assert sorted(nx.edge_boundary(P10, [3, 4, 5, 6, 7])) == [
          (3, 2),
          (7, 8),
      ]
      assert list(nx.edge_boundary(P10, [8, 9, 10])) == [(8, 7)]
      assert sorted(nx.edge_boundary(P10, [4, 5, 6], [9, 10])) == []
      assert list(nx.edge_boundary(P10, [1, 2, 3], [3, 4, 5])) == [
          (2, 3),
          (3, 4),
      ]
  
imports: from itertools import combinations
  import pytest
  import networkx
  from networkx import convert_node_labels_to_integers
  from networkx.utils import edges_equal
label_desc: Use image node_id 2 for calling the TestEdgeBoundary obj's underlying member method code with example usage: obj.test_path_graph() without return types