code: def linear_activation_constraint(
      net_block, net, layer_block, layer, add_constraint=True
  ):
      r"""
      Linear activation constraint generator
  
      Generates the constraints for the linear activation function:
  
      .. math::
  
          \begin{align*}
              y=x
          \end{align*}
  
      """
  
      @layer_block.Constraint(layer.output_indexes)
      def linear_activation(b, *output_index):
          zhat_lb, zhat_ub = b.zhat[output_index].bounds
          b.z[output_index].setlb(zhat_lb)
          b.z[output_index].setub(zhat_ub)
          return b.z[output_index] == b.zhat[output_index]
  
label_desc: Use image node_id 2 for calling a global function with example usage: linear_activation_constraint(net_block, net, layer_block, layer, add_constraint) and returns: unknown