code: def forward(self, x):
      x_shape = paddle.shape(x)
      N, C = x_shape[1], x_shape[2]
      qkv = (
          self.qkv(x)
          .reshape((-1, N, 3, self.num_heads, C // self.num_heads))
          .transpose((2, 0, 3, 1, 4))
      )
      q, k, v = qkv[0], qkv[1], qkv[2]
  
      attn = (q.matmul(k.transpose((0, 1, 3, 2)))) * self.scale
      attn = nn.functional.softmax(attn, axis=-1)
      attn = self.attn_drop(attn)
  
      x = (attn.matmul(v)).transpose((0, 2, 1, 3)).reshape((-1, N, C))
      x = self.proj(x)
      x = self.proj_drop(x)
      return x
  
imports: import os
  import math
  import paddle
  import paddle.nn
  import paddle.nn.functional
  import numpy
  from paddleseg.cvlibs import manager
  from paddleseg.utils import utils, logger
  from paddleseg.models.backbones.transformer_utils import to_2tuple, DropPath, Identity
label_desc: Use image node_id 2 for calling the Attention obj's underlying member method code with example usage: obj.forward(x) and returns: x