code: def test_select_starting_cell_error(self):
      G = nx.diamond_graph()
      pytest.raises(
          nx.NetworkXError, line._select_starting_cell, G, (4, 0)
      )
      pytest.raises(
          nx.NetworkXError, line._select_starting_cell, G, (0, 3)
      )
  
imports: import pytest
  import networkx
  from networkx.generators import line
  from networkx.utils import edges_equal
label_desc: Use image node_id 3 for calling the TestGeneratorPrivateFunctions obj's underlying member method code with example usage: obj.test_select_starting_cell_error() without return types