<?xml version='1.0' encoding='UTF-8' ?>

<Envelope xmlns="http://schemas.xmlsoap.org">
    <Id>1</Id>
    <Method>
        <Name>subtract</Name>
        <Params>
            <Param>42</Param>
            <Param>23</Param>
        </Params>
    </Method>
</Envlope>

<?xml version='1.0' encoding='UTF-8' ?>

<Envelope xmlns="http://schemas.xmlsoap.org">
    <Id>1</Id>
    <Result>19</Result>
</Envlope>