code: def forward(self, *input):
      x1 = self.pre_conv1(input[0])
      x2 = self.pre_conv2(input[1])
      if self.factor > 1:
          padding, out_padding = get_padding(
              x1.size(), x2.size(), self.factor
          )
          x2 = F.conv_transpose2d(
              x2,
              self.deconv_weight,
              stride=self.factor,
              padding=padding,
              output_padding=out_padding,
          )
      return x1 + x2
  
imports: import torch.nn.functional
  from .utils import *
  from .backbone import *
label_desc: Use image node_id 2 for calling the Refine_block2_1 obj's underlying member method code with example usage: obj.forward() and returns: unknown