code: def testAdjacency(self):
      with temporary_file(
          """\
          # Test comment line
          0 1 1 0 0 0
          1 0 1 0 0 0
          1 1 0 0 0 0
          0 0 0 0 2 2
          0 0 0 2 0 2
          0 0 0 2 2 0
          """
      ) as tmpfname:
          g = Graph.Read_Adjacency(tmpfname)
          self.assertTrue(isinstance(g, Graph))
          self.assertEqual(g.vcount(), 6)
          self.assertEqual(g.ecount(), 18)
          self.assertTrue(g.is_directed())
          self.assertTrue("weight" not in g.edge_attributes())
  
          g = Graph.Read_Adjacency(tmpfname, attribute="weight")
          self.assertTrue(isinstance(g, Graph))
          self.assertEqual(g.vcount(), 6)
          self.assertEqual(g.ecount(), 12)
          self.assertTrue(g.is_directed())
          self.assertTrue(
              g.es["weight"] == [1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2]
          )
  
          g.write_adjacency(tmpfname)
  
imports: import gzip
  import io
  import unittest
  import warnings
  from igraph import Graph, InternalError
  from .utils import temporary_file
label_desc: Use image node_id 8 for calling the ForeignTests obj's underlying member method code with example usage: obj.testAdjacency() without return types