I used to use the AddFuture() function to request Future data. But I found the AddFutureContract() function and thought it will be more straightforward to use it if I only want to get the data of the front month contract. To use it, I have to create the Symbol object of the front month contract but I cannot find any sample code about it. Say, I want to trade the front month contract of CL (WTI crude oil), how can I create the Symbol object for the front month contract given the future symbol string 'CL'?