code: def toy_function(x):
      return -(x**4) + 3 * x**2 - 5 * np.sin(x) + 1
  
file_path: ReAgent/reagent/test/training/test_probabilistic.py
imports: import logging
  import unittest
  import numpy
  import pytorch_lightning
  import reagent.core.types
  import torch
  import torch.optim
  from reagent.models.probabilistic_fully_connected_network import FullyConnectedProbabilisticNetwork
  from reagent.training.cfeval.bayes_by_backprop_trainer import BayesByBackpropTrainer
label_desc: Use image node_id 1 for calling a global function with example usage: toy_function(x) and returns: unknown