code: def forward(self, x1: torch.Tensor, x2: torch.Tensor) -> torch.Tensor:
      if self.up_flag:
          x1 = F.interpolate(
              x1,
              size=x2.shape[2:],
              mode="bilinear",
              align_corners=False,
          )
      return self.relu(self.bn(self.conv(torch.cat([x1, x2], dim=1))))
  
imports: from typing import Union, List
  import torch
  import torch.nn
  import torch.nn.functional
label_desc: Use image node_id 2 for calling the UpConvBNReLU obj's underlying member method code with example usage: obj.forward(x1, x2) and returns: self