How to use the pyrfc.ABAPApplicationError function in pyrfc

self.conn.call("RFC_RAISE_ERROR", METHOD="1", MESSAGETYPE="E")
        except pyrfc.ABAPApplicationError as ex:
            error = get_error(ex)
            assert error["code"] == 5
            assert error["key"] == "RAISE_EXCEPTION"
            assert error["msg_class"] == u"SR"
            assert error["msg_type"] == "E"
            assert error["msg_number"] == "006"
            # Assures that the connection handle is correctly synchronized
            self.conn.call("RFC_PING")

        # '2_E': 'ABAPApplicationError-5-RAISE_EXCEPTION- Number:000-True',
        # cf. ExceptionTest.c (l. 65ff)
        try:
            self.conn.call("RFC_RAISE_ERROR", METHOD="2", MESSAGETYPE="E")
        except pyrfc.ABAPApplicationError as ex:
            error = get_error(ex)
            assert error["code"] == 5
            assert error["key"] == "RAISE_EXCEPTION"
            assert error["msg_number"] == "006"
            self.conn.call("RFC_PING")

def my_sftc_connection_error(request_context, REQUTEXT):
    # depending on the REQUTEXT value, raises errors.
    if REQUTEXT == 'EXCEPTION':
        raise ABAPApplicationError(key='BAD_EXCEPTION_HAPPENED')
    elif REQUTEXT == 'EXCEPTION_MESSAGE':
        raise ABAPApplicationError(key='BAD_EXCEPTION_W_MSG',
            msg_class='SR', # message id or class
            msg_type='E', # out of e.g. 'E', 'A' or 'X'
            msg_number='007', # 3 char numeric
            msg_v1='V1 text' # 50 char
        )
    elif REQUTEXT == 'MESSAGE':
        raise ABAPRuntimeError(
            msg_class='SM', # message id or class
            msg_type='E', # out of e.g. 'E', 'A' or 'X'
            msg_number='107', # 3 char numeric string
            msg_v1='V1 text (ABAP_MESSAGE)'
        )
    elif REQUTEXT == 'FAILURE':
        raise ExternalRuntimeError("Something very bad happened.")

def test_RFC_RAISE_ERROR_AbapApplicationError_E1(self):
        # Comment: cf. result_print of the error_test.py
        # '1_E': 'ABAPApplicationError-5-RAISE_EXCEPTION-ID:SR Type:E Number:006 STRING-True',
        # cf. ExceptionTest.c (l. 75ff)
        try:
            self.conn.call("RFC_RAISE_ERROR", METHOD="1", MESSAGETYPE="E")
        except pyrfc.ABAPApplicationError as ex:
            assert self.conn.alive == True
            error = get_error(ex)
            assert error["code"] == 5
            assert error["key"] == "RAISE_EXCEPTION"
            assert error["msg_class"] == u"SR"
            assert error["msg_type"] == "E"
            assert error["msg_number"] == "006"

def test_call_non_existing_RFM(self):
        try:
            self.conn.call("undefined")
        except pyrfc.ABAPApplicationError as ex:
            error = get_error(ex)
        assert error["code"] == 5
        assert error["key"] == "FU_NOT_FOUND"
        assert error["message"][0] == "ID:FL Type:E Number:046 undefined"

def my_sftc_connection_error(request_context, REQUTEXT):
    # depending on the REQUTEXT value, raises errors.
    if REQUTEXT == 'EXCEPTION':
        raise ABAPApplicationError(key='BAD_EXCEPTION_HAPPENED')
    elif REQUTEXT == 'EXCEPTION_MESSAGE':
        raise ABAPApplicationError(key='BAD_EXCEPTION_W_MSG',
            msg_class='SR', # message id or class
            msg_type='E', # out of e.g. 'E', 'A' or 'X'
            msg_number='007', # 3 char numeric
            msg_v1='V1 text' # 50 char
        )
    elif REQUTEXT == 'MESSAGE':
        raise ABAPRuntimeError(
            msg_class='SM', # message id or class
            msg_type='E', # out of e.g. 'E', 'A' or 'X'
            msg_number='107', # 3 char numeric string
            msg_v1='V1 text (ABAP_MESSAGE)'
        )
    elif REQUTEXT == 'FAILURE':
        raise ExternalRuntimeError("Something very bad happened.")
    elif REQUTEXT == 'INVALID':
        raise RFCError("Invalid exception")

def test_server_error(self):
        server = Server(config={'debug': True}, **config._sections['gateway'])
        test = _Testing()

        # Install two functions
        func_desc_conn = self.conn.get_function_description("STFC_CONNECTION")
        server.install_function(
            func_desc_conn,
            my_sftc_connection_error
        )

        with self.assertRaises(ABAPApplicationError) as run:
            test.invoke_srv_function("STFC_CONNECTION", REQUTEXT="EXCEPTION")
        self.assertEqual(run.exception.code, 5, "rc")
        self.assertEqual(run.exception.key, "BAD_EXCEPTION_HAPPENED")

        with self.assertRaises(ABAPApplicationError) as run:
            test.invoke_srv_function("STFC_CONNECTION", REQUTEXT="EXCEPTION_MESSAGE")
        self.assertEqual(run.exception.code, 5, "rc")
        self.assertEqual(run.exception.key, "BAD_EXCEPTION_W_MSG")
        self.assertEqual(run.exception.msg_class, "SR")
        self.assertEqual(run.exception.msg_type, "E")
        self.assertEqual(run.exception.msg_number, "007")
        self.assertEqual(run.exception.msg_v1, "V1 text")

        with self.assertRaises(ABAPRuntimeError) as run:
            test.invoke_srv_function("STFC_CONNECTION", REQUTEXT="MESSAGE")
        self.assertEqual(run.exception.code, 4, "rc")