code: def testDeBruijn(self):
      g = Graph.De_Bruijn(2, 3)
      deg_in = g.degree(mode="in", loops=True)
      deg_out = g.degree(mode="out", loops=True)
      # This is not a proper test, but should spot most errors
      self.assertTrue(
          g.is_directed() and deg_in == [2] * 8 and deg_out == [2] * 8
      )
  
imports: import unittest
  from igraph import Graph, InternalError
label_desc: Use image node_id 10 for calling the GeneratorTests obj's underlying member method code with example usage: obj.testDeBruijn() without return types