How to use the ocpp.messages.MessageType function in ocpp

def get_schema(message_type_id, action, ocpp_version, parse_float=float):
    """
    Read schema from disk and return in. Reads will be cached for performance
    reasons.

    The `parse_float` argument can be used to set the conversion method that
    is used to parse floats. It must be a callable taking 1 argument. By
    default it is `float()`, but certain schema's require `decimal.Decimal()`.
    """
    if ocpp_version not in ["1.6", "2.0"]:
        raise ValueError

    schemas_dir = 'v' + ocpp_version.replace('.', '')

    schema_name = action
    if message_type_id == MessageType.CallResult:
        schema_name += 'Response'
    elif message_type_id == MessageType.Call:
        if ocpp_version == "2.0":
            schema_name += 'Request'

    if ocpp_version == "2.0":
        schema_name += '_v1p0'

    dir,  _ = os.path.split(os.path.realpath(__file__))
    relative_path = f'{schemas_dir}/schemas/{schema_name}.json'
    path = os.path.join(dir, relative_path)

    if relative_path in _schemas:
        return _schemas[relative_path]

    # The JSON schemas for OCPP 2.0 start with a byte order mark (BOM)

If the message is a of type Call the corresponding hooks are executed.
        If the message is of type CallResult or CallError the message is passed
        to the call() function via the response_queue.
        """
        try:
            msg = unpack(raw_msg)
        except OCPPError as e:
            LOGGER.exception("Unable to parse message: '%s', it doesn't seem "
                             "to be valid OCPP: %s", raw_msg, e)
            return

        if msg.message_type_id == MessageType.Call:
            await self._handle_call(msg)
        elif msg.message_type_id in \
                [MessageType.CallResult, MessageType.CallError]:
            self._response_queue.put_nowait(msg)