class_docstr: This class defines the ESP block, which is based on the following principle
      Reduce ---> Split ---> Transform --> Merge
class_docstr_tok: ["This","class","defines","the","ESP","block",",","which","is","based","on","the","following","principle","Reduce","--","-",">","Split","--","-",">","Transform","--",">","Merge"]
code: def forward(self, input):
      output1 = self.c1(input)
      output1 = channel_shuffle(output1, self.group_n)
      res_0 = self.layer_0(output1)
      res_1 = self.layer_1(output1)
      combine = paddle.concat([res_0, res_1], 1)
  
      if self.add:
          combine = input + combine
      output = self.BR(combine)
      return output
  
imports: import paddle
  import paddle.nn
  import paddle.nn.functional
  from paddleseg.models import layers
  from paddleseg.cvlibs import manager
  from paddleseg.utils import utils
label_desc: Use image node_id 2 for calling the S2module obj's underlying member method code with example usage: obj.forward(input) and returns: output