text: import unittest
  from grammar import Grammar
  
  class TestSequitur(unittest.TestCase):
      def test_sequitur(self):
          """docstring for test_sequitur"""
          g = Grammar()
          g.train_string("Hello, world!")
          
          self.assertEqual("0 --(0)--> H e l l o , _ w o r l d ! \n", g.print_grammar())
  
      def test_sequitur_base(self):
          """docstring for test_sequitur_base"""
          g = Grammar()
          g.train_string("abcabdabcabd")
  
          self.assertEqual("0 --(0)--> 1 1 \n1 --(2)--> 2 c 2 d                                       abcabd\n2 --(2)--> a b                                           ab\n", g.print_grammar())
  
  if __name__ == '__main__':
      unittest.main()
  