How to read Firebase "array" object in Android pojo?

[TheKreshendo]

I posted this question on stackoverflow already, but maybe someone here can help me out. I am trying to create a POJO in my android app to map to data I have saved in firebase. The POJO is a nested object and I have achieved partial success. I believe my problem is coming from how firebase stores arrays. In the web version of my application, I create a simple array of integers and save it to the real-time database. The array is never altered again but I do need to read it in the android application. 

For more details, refer to my stackoverflow question here. 

I just want to know how I should structure the POJO so it can read the contents of the array object if the Keys are integers (0-9).  

I have tried using hashmaps, Lists (with types strings, integers, and longs), and arraylists. All have still resulted in the metaData object still being null at runtime.