code: def test_dynamic_duck_size(self):
      def fn(a, b):
          if a.size(0) == b.size(0):
              return a + b
          else:
              return a.sum() + b.sum()
  
      torch._dynamo.reset()
      cnt_dynamic = torch._dynamo.testing.CompileCounter()
      opt_fn = torch._dynamo.optimize(cnt_dynamic, dynamic=True)(fn)
      x = torch.randn(2)
      y = torch.randn(3)
      self.assertEqual(opt_fn(x, x), fn(x, x))
      self.assertEqual(opt_fn(x, y), fn(x, y))
      self.assertEqual(cnt_dynamic.frame_count, 2)
  
imports: from unittest.mock import patch
  import torch
  import torch._dynamo.test_case
  import torch._dynamo.testing
  from torch._dynamo.testing import unsupported
  from torch._dynamo.utils import ifdynstaticdefault
label_desc: Use image node_id 33 for calling the SubGraphTests obj's underlying member method code with example usage: obj.test_dynamic_duck_size() and returns: unknown, unknown