code: def test_reber_word_generation(self):
      words = make_reber(50)
      self.assertEqual(50, len(words))
  
      for word in words:
          self.assertTrue(is_valid_by_reber(word))
  
file_path: neupy/tests/datasets/test_reber.py
imports: import math
  import numpy
  from neupy.datasets.reber import avaliable_letters
  from neupy.datasets import make_reber, is_valid_by_reber, make_reber_classification
  from base import BaseTestCase
label_desc: Use image node_id 1 for calling the ReberTestCase obj's underlying member method code with example usage: obj.test_reber_word_generation() without return types