To override the Content-type in your clients, use the HTTP Accept Header, append  the .csv suffix or  ?format=csv
        
        HTTP + CSV
         The following are sample HTTP requests and responses. 
            The placeholders shown need to be replaced with actual values.
POST /documents/extendSas HTTP/1.1 
Host: initiation-pen.sirva.com 
Accept: text/csv
Content-Type: text/csv
Content-Length: length
{"FileName":"String","Month":0,"Day":0,"ExternalId":"String"}
 
HTTP/1.1 200 OK
Content-Type: text/csv
Content-Length: length
{"Link":"String","Message":"String","IsSuccess":false}