def test_1(self):
     a = 'abcdcdefgh'
     b ='bcd'
     self.assertEqual(strStr.strStr_2(a,b),1)
 def test_3(self):
     a = None
     b = 'abcd'
     self.assertEqual(strStr.strStr_2(a,b),-1)
 def test_5(self):
     a ='abcd'
     b ='ab'
     self.assertEqual(strStr.strStr_2(a,b),0)
 def test_2(self):
     a = ''
     b = ''
     self.assertEqual(strStr.strStr_2(a,b),0)