code: def forward(self, pred, target):
      return torch.tensor(1.0)
  
file_path: ClassyVision/test/losses_multi_output_sum_loss_test.py
imports: import unittest
  import torch
  from classy_vision.losses import build_loss, ClassyLoss, MultiOutputSumLoss, register_loss
label_desc: Use image node_id 1 for calling the MockLoss1 obj's underlying member method code with example usage: obj.forward(pred, target) and returns: torch