code: def forward(self, logits, target):
      return _lovasz_softmax(
          logits,
          target,
          per_image=self.per_image,
          ignore_index=self.ignore,
      )
  
imports: from __future__ import print_function, division
  from typing import Optional, Union
  import torch
  import torch.nn.functional
  from torch.autograd import Variable
  from torch.nn.modules.loss import _Loss
label_desc: Use image node_id 2 for calling the LovaszLoss obj's underlying member method code with example usage: obj.forward(logits, target) and returns: _lovasz_softmax