old_contents: import chainer
  
  from lib.node import Input, Output, Function
  
  
  class Relu(Function):
      Input('in_array', chainer.Variable)
      Output('out_array', chainer.Variable)
  
      def call(self):
          return "relu("
  
  
  class Sigmoid(Function):
      Input('in_array', chainer.Variable)
      Output('out_array', chainer.Variable)
  
      def call(self):
          return "sigmoid("
  
  
  class Tanh(Function):
      Input('in_array', chainer.Variable)
      Output('out_array', chainer.Variable)
  
      def call(self):
          return "tanh("
  
new_contents: import chainer
  
  from lib.node import Input, Output, Function
  
  
  class Relu(Function):
      Input('in_array', chainer.Variable)
      Output('out_array', chainer.Variable)
  
      def call(self):
          return 'relu('
  
  
  class Sigmoid(Function):
      Input('in_array', chainer.Variable)
      Output('out_array', chainer.Variable)
  
      def call(self):
          return 'sigmoid('
  
  
  class Tanh(Function):
      Input('in_array', chainer.Variable)
      Output('out_array', chainer.Variable)
  
      def call(self):
          return 'tanh('
  
  
  class Dropout(Function):
      Input('in_array', chainer.Variable)
      Input('ratio', float)
      Output('out_array', chainer.Variable)
  
      def call(self):
          return 'dropout(ratio=ratio, x='
  
subject: Add dropout