error in running the last cell of Viz.ipynb

[saeedehghanadbashi]

Hi, when I tried to run the following cell, I got the attached error. Would you please let me know what is the problem?

Bounded region of parameter space

pbounds = {'lr': (1e-2, 1e-4), 'bs':(5_000, 100_000), 'eps':(0.01, 0.2), 'final_eps': (0.01, 0.02)}
optimizer = BayesianOptimization(
f=fit_with,
pbounds=pbounds,
verbose=2
)

optimizer.maximize(init_points=2, n_iter=5,)

for i, res in enumerate(optimizer.res):
print("Iteration {}: \n\t{}".format(i, res))

print('Max', optimizer.max)