code: def forward(self, input):
      n, c, h, w = input.shape
      # B, C, H, W
      reduction_dim = self.reduction_dim(input)
      # B, N, H, W
      mat_B = self.projection_mat(input)
      # B, C, H*W
      reshaped_reduction = paddle.reshape(
          reduction_dim, shape=[n, self.num_state, h * w]
      )
      # B, N, H*W
      reshaped_B = paddle.reshape(
          mat_B, shape=[n, self.num_node, h * w]
      )
      # B, N, H*W
      reproject = reshaped_B
      # B, C, N
      node_state_V = paddle.matmul(
          reshaped_reduction,
          paddle.transpose(reshaped_B, perm=[0, 2, 1]),
      )
  
      if self.normalize:
          node_state_V = node_state_V * (
              1.0 / reshaped_reduction.shape[2]
          )
  
      # B, C, N
      gcn_out = self.gcn(node_state_V)
      # B, C, H*W
      Y = paddle.matmul(gcn_out, reproject)
      # B, C, H, W
      Y = paddle.reshape(Y, shape=[n, self.num_state, h, w])
      Y_extend = self.extend_dim(Y)
      Y_extend = self.extend_bn(Y_extend)
  
      out = input + Y_extend
      return out
  
imports: import paddle
  import paddle.nn
  import paddle.nn.functional
  from paddleseg.cvlibs import manager
  from paddleseg.models import layers
  from paddleseg.utils import utils
label_desc: Use image node_id 2 for calling the GruModule obj's underlying member method code with example usage: obj.forward(input) and returns: out