code: def test_return_nx_graph(self):
      # only testing that return_nx_graph produces no errors
      #     work in progress!
  
      pytest.importorskip("networkx")
      pytest.importorskip("pandas", minversion="0.17.0")
  
      self.g.return_nx_graph(False, False)
      self.g.return_nx_graph(False, True)
      self.g.return_nx_graph(True, False)
      self.g.return_nx_graph("color", "dx")
      self.g.return_nx_graph(["color"], ["dx", "dt"])
      self.g_si.return_nx_graph(["color"], ["dx", "dt"])
  
      # test dropna
      nxg = self.g.return_nx_graph(
          ["color"], ["dx", "dt"], dropna="none"
      )
      assert nxg.number_of_edges() == 7
  
      nxg = self.g.return_nx_graph(
          ["color"], ["dx", "dt"], dropna="all"
      )
      assert nxg.number_of_edges() == 6
  
      nxg = self.g.return_nx_graph(
          ["color"], ["dx", "dt"], dropna="any"
      )
      assert nxg.number_of_edges() == 2
  
imports: import pytest
  import numpy
  import pandas
  from pandas.testing import assert_frame_equal
  from numpy.testing import assert_allclose
  from deepgraph import DeepGraph
label_desc: Use image node_id 2 for calling the TestInterfaces obj's underlying member method code with example usage: obj.test_return_nx_graph() without return types