I would like to create xml schema on nusoap like the following:

<xsd:complexType name="WSMessage">
    <xsd:sequence>
        <xsd:element minOccurs="0" maxOccurs="1" name="ErrorMessage" type="s:string"/>
        <xsd:element minOccurs="0" maxOccurs="1" name="ErrorCode" type="s:string"/>
    </xsd:sequence>
</xsd:complexType>
<s:complexType name="ResultSet">
    <s:complexContent mixed="false">
        <s:extension base="tns:WSMessage">
            <s:sequence>
                <s:element minOccurs="0" maxOccurs="1" name="TestData" type="tns:ArrayOfTestData"/>
            </s:sequence>
        </s:extension>
    </s:complexContent>
</s:complexType>

I can't see any documentation on how I could do that. Does anyone know this already? Thank you.