code: def step_function(self, x, y):
      return paddle.reciprocal(1 + paddle.exp(-self.k * (x - y)))
  
file_path: PaddleOCR/benchmark/PaddleOCR_DBNet/models/head/DBHead.py
imports: import paddle
  from paddle import nn, ParamAttr
label_desc: Use image node_id 5 for calling the DBHead obj's underlying member method code with example usage: obj.step_function(x, y) and returns: paddle