def getCliInstance():
	global _dbcli
	if not _dbcli:
		_dbcli = DatabaseHelper()
	return _dbcli
def test_exceptions(self):
        self.assert_(issubclass(DeoptionError, TypeError))
        self.assertRaises(TypeError,
            lambda: Optional()
        )
        self.assertRaises(TypeError,
            lambda: Optional(NotPassed, NotPassed)
        )