code: def sigmoid(self, input, name):
      fluid = import_fluid()
      return fluid.layers.sigmoid(
          input, name=self.get_unique_output_name(name, "sigmoid")
      )
  
imports: from __future__ import print_function
  from builtins import str
  from past.builtins import basestring
  from builtins import object
  import sys
  import os
  import math
  import numpy
label_desc: Use image node_id 15 for calling the Network obj's underlying member method code with example usage: obj.sigmoid(input, name) and returns: fluid