public KnetikApiResponse CartModify(
int catalogId,
int catalogSkuId,
int quantity,
Action<KnetikApiResponse> cb = null
)
{
JSONObject j = new JSONObject (JSONObject.Type.OBJECT);
j.AddField ("catalog_id", catalogId);
j.AddField ("catalog_sku_id", catalogSkuId);
j.AddField ("quantity", quantity);
String body = j.Print ();
KnetikRequest req = CreateRequest(CartModifyEndpoint, body);
KnetikApiResponse response = new KnetikApiResponse(this, req, cb);
return response;
}