Here is some cut/paste code you can use in "Interpreter" tab to test test data file:

print(data.size());

print(data.keySet());

print(data.get("doc").keySet());

print(data.get("doc","age",int.class));

for(String s : data.get("doc").keySet())
{
    print(s + " = " + data.get("doc",s));
}

