code: def set_learning_rate(optimizer, lr):
      for group in optimizer.param_groups:
          group["lr"] = lr
  
imports: import argparse
  import os
  import math
  import matplotlib.pyplot
  import torch
  import torch.nn
  from torchdiffeq import odeint, odeint_event
  from bouncing_ball import BouncingBallExample
label_desc: Use image node_id 4 for calling a global function with example usage: set_learning_rate(optimizer, lr) without return types