Remove <result> node from SOAP API response in Magento 2

Question

I need to remove the node from SOAP API response Magento 2. Below is an example. From:

<env:Body>
    <ns1:customTestAuthV1CallbackResponse>
        <result>
            <resultCode>1</resultCode>
            <resultMessage>response message</resultMessage>
        </result>
    </ns1:customTestAuthV1CallbackResponse>
</env:Body>

To

<env:Body>
    <ns1:customTestAuthV1CallbackResponse>
        <resultCode>1</resultCode>
        <resultMessage>response message</resultMessage>
    </ns1:customTestAuthV1CallbackResponse>
</env:Body>

I have created a module to remove the node from response but it is throwing an error as seen below

<env:Fault>
    <env:Code>
        <env:Value>env:Receiver</env:Value>
    </env:Code>
    <env:Reason>
        <env:Text>SOAP-ERROR: Encoding: object has no 'result' property</env:Text>
    </env:Reason>
</env:Fault>

Does anyone have any idea how can we remove the node?