code: def test_autocast_decorator(self):
      def autocast_func(orig_func):
          @torch.amp.autocast(device_type="cuda", dtype=torch.float16)
          def new_fwd(*args, **kwargs):
              return orig_func(*args, **kwargs)
  
          return new_fwd
  
      def autocast_func_cuda(orig_func):
          @torch.cuda.amp.autocast(dtype=torch.float16)
          def new_fwd(*args, **kwargs):
              return orig_func(*args, **kwargs)
  
          return new_fwd
  
      def autocast_func_cpu(orig_func):
          @torch.cpu.amp.autocast(dtype=torch.float16)
          def new_fwd(*args, **kwargs):
              return orig_func(*args, **kwargs)
  
          return new_fwd
  
      def mm(a, b):
          return torch.mm(a, b)
  
      mm_float16 = autocast_func(mm)
      mm_float16_cuda = autocast_func_cuda(mm)
      mm_float16_cpu = autocast_func_cpu(mm)
  
      def fn(a, b):
          return (
              mm_float16(a, b),
              mm_float16_cuda(a, b),
              mm_float16_cpu(a, b),
          )
  
      a_float32 = torch.rand((8, 8), device="cuda")
      b_float32 = torch.rand((8, 8), device="cuda")
  
      ref = fn(a_float32, b_float32)
      opt_fn = torch.compile(backend="eager", fullgraph=True)(fn)
      res = opt_fn(a_float32, b_float32)
      self.assertTrue(same(ref, res))
      self.assertTrue(res[0].dtype == torch.float16)
      self.assertTrue(res[1].dtype == torch.float16)
  
imports: import unittest
  import torch
  import torch._dynamo.test_case
  import torch._dynamo.testing
  import torch.onnx.operators
  from torch._dynamo.testing import EagerAndRecordGraphs, normalize_gm, same
  from torch.nn import functional
  from torch.testing._internal.common_cuda import PLATFORM_SUPPORTS_FLASH_ATTENTION
  from torch.testing._internal.common_utils import TEST_WITH_ROCM
label_desc: Use image node_id 24 for calling the CtxManagerTests obj's underlying member method code with example usage: obj.test_autocast_decorator() and returns: new_fwd, new_fwd, new_fwd, torch, mm_float16,  mm_float16_cuda,  mm_float16_cpu, orig_func, orig_func, orig_func