Hi, I understand you are referring to the custom wrapper sample included in $DENODO_HOME/samples/vdp/customWrappers. Yes, this custom wrapper retrieves data from a Salesforce account using SOAP but it is only for sample purposes to learn how to build a custom data source in Denodo using an external API (Salesforce SOAP API) so you can use it to extend that example or use a completely different API! Cool! ;)
By the way, if you are looking for Salesforce/Denodo integration, maybe it's interesting for you to know that there is a more complete connector that allows to perform CRUD operations against SalesForce in an SQL-way (but it is available only for Denodo customers with full license).
Hope this helps!