code: def swish(x):
      r"""Swish activation function:
  
      .. math::
          \text{Swish}(x) = \frac{x}{1 + \exp(-x)}
      """
      return x.mul(torch.sigmoid(x))
  
imports: import numpy
  from copy import deepcopy
  import torch
  import torch.nn
  import torch.nn.functional
  from recbole.model.abstract_recommender import GeneralRecommender, AutoEncoderMixin
  from recbole.model.init import xavier_normal_initialization
  from recbole.utils import InputType
label_desc: Use image node_id 1 for calling a global function with example usage: swish(x) and returns: x