code: def __call__(self, preds: Tensor, truth: Tensor) -> Tensor:
      return F.mse_loss(preds, truth, reduction="none")
  
imports: from typing import TYPE_CHECKING, Optional
  import torch
  from torch import Tensor, BoolTensor
  from torch.nn import functional
label_desc: Use image node_id 1 for calling the MSELoss obj's underlying member method code with example usage: obj.__call__(preds, truth) and returns: F