code: def f4(x):
      return x**5.0 - 5 * x**3.0 - 20.0 * x + 5.0
  
imports: import pytest
  import numpy
  from numpy.testing import assert_allclose, assert_equal, assert_array_less
  from scipy import stats
  import scipy.optimize._chandrupatla
  from scipy.optimize._chandrupatla import _chandrupatla_minimize
  from itertools import permutations
label_desc: Use image node_id 4 for calling a global function with example usage: f4(x) and returns: unknown