input: Write a python function to create a 3x3x3 numpy array filled with zeros.
  assert np.array_equal(create_zeros_array(), np.zeros((3, 3, 3)))
  assert create_zeros_array().shape == (3, 3, 3)
  assert create_zeros_array().dtype == float
output: def create_zeros_array():
      import numpy as np
      return np.zeros((3, 3, 3))