input: Write a python function to create and display a 3-D numpy array.
  assert np.array_equal(create_and_display_3d_array(), np.array([[[1, 2, 3], [4, 5, 6]], [[7, 8, 9], [10, 11, 12]]]))
output: def create_and_display_3d_array():
      import numpy as np
      arr = np.array([[[1, 2, 3], [4, 5, 6]], [[7, 8, 9], [10, 11, 12]]])
      print(arr)
      return arr