Even if you manage to get over the error, the function will not do what you intend it to do. The callback you are creating will be notified asynchronously of the response received from server while your method populateRSSData() will return immediately.
An easy way out - declare data as a list of Strings and make the list final. You can always add elements to final list (you just can`t assign a different list to the final variable).
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.