code: def test_stable_topological_sort(self):
      def fn1(a, b):
          return a + b
  
      graph = torch.fx.Graph()
      a = graph.placeholder("x")
      b = graph.placeholder("y")
      c = graph.call_function(fn1, (a, b))
      stable_topological_sort(graph)
      self.assertEqual(list(graph.nodes), [a, b, c])
  
      graph = torch.fx.Graph()
      b = graph.placeholder("y")
      a = graph.placeholder("x")
      c = graph.call_function(fn1, (a, b))
      stable_topological_sort(graph)
      self.assertEqual(list(graph.nodes), [b, a, c])
  
      graph = torch.fx.Graph()
      a = graph.placeholder("x")
      b = graph.placeholder("y")
      c = graph.call_function(fn1, (b, a))
      c.append(a)
      stable_topological_sort(graph)
      self.assertEqual(list(graph.nodes), [b, a, c])
  
imports: import copy
  import unittest
  import torch
  import torch._dynamo.config
  import torch._inductor.config
  from torch._dynamo.test_case import run_tests, TestCase
  from torch._dynamo.utils import count_calls, counters
  from torch._higher_order_ops.out_dtype import out_dtype
  from torch._inductor.fx_passes import joint_graph
  from torch._inductor.fx_passes.serialized_patterns.central_index import get_serialized_pattern
  from torch._inductor.pattern_matcher import _TargetExpr, Arg, CallFunction, gen_pattern, KeywordArg, Match, PatternExpr, PatternMatcherPass, PatternPrettyPrinter, register_graph_pattern, stable_topological_sort
  from torch._inductor.utils import run_and_get_code
  from torch._inductor.virtualized import V
  from torch.testing import FileCheck
  from torch.testing._internal.common_cuda import SM80OrLater
  from torch.testing._internal.common_utils import IS_LINUX, skipIfRocm
  from torch.testing._internal.inductor_utils import HAS_CUDA
label_desc: Use image node_id 35 for calling the TestPatternMatcher obj's underlying member method code with example usage: obj.test_stable_topological_sort() and returns: unknown