code: def setUpClass(cls):
      b1 = tl.alphas([4, 3, 2, 1], 0.5431)
      b2 = tl.alphas([4, 3, 2], 5)
      b3 = tl.alphas([1, 2, 3, 4], -5)
      b4 = tl.alphas([2, 3, 4], True)
  
      with tf.Session() as sess:
          cls._b1, cls._b2, cls._b3, cls._b4 = sess.run(
              [b1, b2, b3, b4]
          )
  
imports: import os
  import unittest
  import numpy
  import tensorflow
  import tensorlayer
  from tests.utils import CustomTestCase
label_desc: Use image node_id 1 for calling the Array_Op_Alphas_Test obj's underlying member method code with example usage: obj.setUpClass(cls) without return types