code: def __init__(self, input_dim, filters, kernel_size=3):
      super(UNetUpStack, self).__init__()
  
      self.scale_factor = 2
      self.stack1 = ConvBNReluStack(
          input_dim, filters, 1, stride=1, padding=0
      )
      self.stack3 = ConvBNReluStack(
          input_dim, filters, 3, stride=1, padding=1
      )
      self.stack5 = ConvBNReluStack(
          input_dim, filters, 5, stride=1, padding=2
      )
      self.stack_pool = nn.AvgPool2d(3, stride=1, padding=1)
      self.reducer = ConvBNReluStack(
          filters * 3 + input_dim,
          filters,
          kernel_size=1,
          stride=1,
          padding=0,
      )
  
imports: import torch
  import torch.nn
  import torch.nn.functional
label_desc: Use image node_id 1 to create a new UNetUpStack object from inherited base classes: nn with example: obj = UNetUpStack(input_dim, filters, kernel_size)