code: def test_reber_expcetions(self):
      with self.assertRaises(ValueError):
          make_reber(n_words=0)
  
      with self.assertRaises(ValueError):
          make_reber(n_words=-1)
  
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 2 for calling the ReberTestCase obj's underlying member method code with example usage: obj.test_reber_expcetions() without return types