code: def extract_patches(self, x, kernel_size, stride):
      n, c, _, _ = x.shape
      x = self.pad(x, kernel_size, stride)
      x = F.unfold(
          x, [kernel_size, kernel_size], strides=[stride, stride]
      )
      x = paddle.transpose(x, (0, 2, 1))
      x = paddle.reshape(x, (n, -1, c, kernel_size, kernel_size))
  
      return x
  
file_path: PaddleSeg/Matting/ppmatting/models/layers/gca_module.py
imports: import paddle
  import paddle.nn
  import paddle.nn.functional
  from paddleseg.cvlibs import param_init
label_desc: Use image node_id 5 for calling the GuidedCxtAtten obj's underlying member method code with example usage: obj.extract_patches(x, kernel_size, stride) and returns: x