'Verify slicing by headers.'

def test_header_slicing(self):

    self.assertEqual(self.founders['first_name'], [self.john[0], self.george[0], self.tom[0]])
    self.assertEqual(self.founders['last_name'], [self.john[1], self.george[1], self.tom[1]])
    self.assertEqual(self.founders['gpa'], [self.john[2], self.george[2], self.tom[2]])
