class_docstr: Base Model for Semantic Segmentation
  
  Parameters
  ----------
  backbone : string
      Pre-trained dilated backbone network type (default:'resnet50'; 'resnet50',
      'resnet101' or 'resnet152').
code: def demo(self, x):
      pred = self.forward(x)
      if self.aux:
          pred = pred[0]
      return pred
  
imports: import torch.nn
  from pywick.models.segmentation.da_basenets.resnetv1b import resnet50_v1s, resnet101_v1s, resnet152_v1s
label_desc: Use image node_id 4 for calling the SegBaseModel obj's underlying member method code with example usage: obj.demo(x) and returns: pred