public KnetikApiResponse UseItem(
int itemID,
Action<KnetikApiResponse> cb = null
)
{
JSONObject j = new JSONObject (JSONObject.Type.OBJECT);
j.AddField ("item_id", itemID);
String body = j.Print ();
KnetikRequest req = CreateRequest(UseItemEndpoint, body);
return new KnetikApiResponse(this, req, cb);
}