code: def parameters(self):
      return [self.radius]
  
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 2 for calling the EventFn obj's underlying member method code with example usage: obj.parameters() and returns: list