Declare NamedTuple at top level (pytorch#53273)

Summary:
Pull Request resolved: pytorch#53273

This prevents a mypy bug.  Fixes pytorch#53272

Signed-off-by: Edward Z. Yang <[email protected]>

Test Plan: Imported from OSS

Reviewed By: rohan-varma

Differential Revision: D26819428

Pulled By: ezyang

fbshipit-source-id: e71575ed13321665a976cc5ef8b2993c00626b7d

Author: ezyang

torch/testing/_internal/distributed/distributed_test.py

@@ -126,6 +126,12 @@ def get_profiling_event(postfix, profiler):
 ddp_outputs_not_used_in_loss_str = "`forward` function outputs participate in calculating loss"
 
 
+class DDPUnevenTestInput(NamedTuple):
+    name: str
+    model: nn.Module
+    inp: Union[torch.tensor, tuple]
+    sync_interval: int
+
 
 class _FC2(nn.Module):
     def __init__(self):
@@ -4090,12 +4096,6 @@ def _run_uneven_inputs_test(
         @require_backends_available({"gloo", "nccl"})
         @skip_if_lt_x_gpu(2)
         def test_ddp_uneven_inputs(self):
-            class DDPUnevenTestInput(NamedTuple):
-                name: str
-                model: nn.Module
-                inp: Union[torch.tensor, tuple]
-                sync_interval: int
-
             dim = 1000
             batch = 1
             # Create a variety of models to run uneven input tests on.