code: def forward(self, x, H, W):
      x = x + self.drop_path(self.attn(self.norm1(x), H, W))
      x = x + self.drop_path(self.mlp(self.norm2(x), H, W))
  
      return x
  
imports: import math
  from functools import partial
  import paddle
  import paddle.nn
  import paddle.nn.functional
  import paddle.nn.initializer
  from paddleseg.cvlibs import manager
  from paddleseg.utils import utils
  from paddleseg.models.backbones.transformer_utils import *
label_desc: Use image node_id 3 for calling the Block obj's underlying member method code with example usage: obj.forward(x, H, W) and returns: x