text: from nose.tools import assert_equal, assert_raises, assert_not_equal
  import cynetworkx as nx
  import io
  import tempfile
  import os
  from cynetworkx.readwrite.p2g import *
  from cynetworkx.testing import *
  
  
  class TestP2G:
  
      def setUp(self):
          self.G = nx.Graph(name="test")
          e = [('a', 'b'), ('b', 'c'), ('c', 'd'), ('d', 'e'), ('e', 'f'), ('a', 'f')]
          self.G.add_edges_from(e)
          self.G.add_node('g')
          self.DG = nx.DiGraph(self.G)
  
      def test_read_p2g(self):
          s = b"""\
  name
  3 4
  a
  1 2
  b
  
  c
  0 2
  """
          bytesIO = io.BytesIO(s)
          G = read_p2g(bytesIO)
          assert_equal(G.name, 'name')
          assert_equal(sorted(G), ['a', 'b', 'c'])
          edges = [(str(u), str(v)) for u, v in G.edges()]
          assert_edges_equal(G.edges(), [('a', 'c'), ('a', 'b'), ('c', 'a'), ('c', 'c')])
  
      def test_write_p2g(self):
          s = b"""foo
  3 2
  1
  1 
  2
  2 
  3
  
  """
          fh = io.BytesIO()
          G = nx.OrderedDiGraph()
          G.name = 'foo'
          G.add_edges_from([(1, 2), (2, 3)])
          write_p2g(G, fh)
          fh.seek(0)
          r = fh.read()
          assert_equal(r, s)
  
      def test_write_read_p2g(self):
          fh = io.BytesIO()
          G = nx.DiGraph()
          G.name = 'foo'
          G.add_edges_from([('a', 'b'), ('b', 'c')])
          write_p2g(G, fh)
          fh.seek(0)
          H = read_p2g(fh)
          assert_edges_equal(G.edges(), H.edges())
  