code: def optimization_step():
      opt.minimize(model.training_loss, model.trainable_variables)
  
file_path: GPflow/notebooks/getting_started/monitoring.pct.py
imports: import os
  import warnings
  import matplotlib
  import matplotlib.pyplot
  import numpy
  import tensorflow
  import gpflow
label_desc: Use image node_id 7 for calling a global function with example usage: optimization_step() without return types