class_docstr: Unit tests for the :func:`~networkx.node_boundary` function.
class_docstr_tok: ["Unit","tests","for","the",":","func",":","`","~networkx.node_boundary","`","function","."]
code: def test_path_graph(self):
      P10 = cnlti(nx.path_graph(10), first_label=1)
      assert nx.node_boundary(P10, []) == set()
      assert nx.node_boundary(P10, [], []) == set()
      assert nx.node_boundary(P10, [1, 2, 3]) == {4}
      assert nx.node_boundary(P10, [4, 5, 6]) == {3, 7}
      assert nx.node_boundary(P10, [3, 4, 5, 6, 7]) == {2, 8}
      assert nx.node_boundary(P10, [8, 9, 10]) == {7}
      assert nx.node_boundary(P10, [4, 5, 6], [9, 10]) == set()
  
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 TestNodeBoundary obj's underlying member method code with example usage: obj.test_path_graph() without return types