code: def forward(self, x):
      x_q = self.q_conv(x).permute(0, 2, 1)  # b, n, c
      x_k = self.k_conv(x)  # b, c, n
      x_v = self.v_conv(x)
      energy = torch.bmm(x_q, x_k)  # b, n, n
      attention = self.softmax(energy)
      attention = attention / (
          1e-9 + attention.sum(dim=1, keepdims=True)
      )
      x_r = torch.bmm(x_v, attention)  # b, c, n
      x_r = self.act(self.after_norm(self.trans_conv(x - x_r)))
      x = x + x_r
      return x
  
imports: import torch
  from helper import TransitionDown
  from torch import nn
label_desc: Use image node_id 2 for calling the SALayerSeg obj's underlying member method code with example usage: obj.forward(x) and returns: x