code: def binary_xloss(logits, labels, ignore=None):
      """
      Binary Cross entropy loss
        logits: [B, H, W] Variable, logits at each pixel (between -infty and +infty)
        labels: [B, H, W] Tensor, binary ground truth masks (0 or 1)
        ignore: void class id
      """
      logits, labels = flatten_binary_scores(logits, labels, ignore)
      loss = StableBCELoss()(logits, Variable(labels.float()))
      return loss
  
imports: import torch
  from torch.autograd import Variable
  import torch.nn.functional
  import numpy
label_desc: Use image node_id 7 for calling a global function with example usage: binary_xloss(logits, labels, ignore) and returns: loss