code: def unscale_l2norm(
      self, sizea, sizeb, applier, repeat_tensors, in_type, per_tensor
  ):
      self.overflow_buf.zero_()
      a = torch.full(
          [sizea], self.val, dtype=torch.float32, device="cuda"
      )
      b = torch.full(
          [sizeb], self.val, dtype=torch.float32, device="cuda"
      )
  
      in_list = []
      for i in range(repeat_tensors):
          in_list += [a.clone().to(in_type), b.clone().to(in_type)]
  
      if per_tensor:
          norm, norm_per_tensor = applier(
              multi_tensor_unscale_l2norm,
              self.overflow_buf,
              [in_list],
              self.inv_scale_cuda,
              True,
          )
          normab = torch.cat(
              (
                  (a * self.inv_scale).norm().view(1),
                  (b * self.inv_scale).norm().view(1),
              )
          )
          norm_per_tensor = norm_per_tensor.view(-1, 2)
      else:
          norm, _ = applier(
              multi_tensor_unscale_l2norm,
              self.overflow_buf,
              [in_list],
              self.inv_scale_cuda,
              True,
          )
  
      reference = torch.full(
          [(sizea + sizeb) * repeat_tensors],
          self.val * self.inv_scale,
          dtype=torch.float32,
          device="cuda",
      ).norm()
  
      torch.testing.assert_close(norm, reference)
      if per_tensor:
          torch.testing.assert_close(norm_per_tensor, normab)
      self.assertTrue(self.overflow_buf.item() == 0)
  
file_path: apex/tests/L0/run_amp/test_multi_tensor_unscale_l2norm.py
imports: import unittest
  import functools
  import itertools
  from apex import amp
  import torch
  from torch import nn
  import torch.nn.functional
  from utils import common_init, HALF, FLOAT, ALWAYS_HALF, ALWAYS_FLOAT, MATCH_INPUT
label_desc: Use image node_id 3 for calling the TestMultiTensorUnscaleL2Norm obj's underlying member method code with example usage: obj.unscale_l2norm(sizea, sizeb, applier, repeat_tensors, in_type, per_tensor) without return types