Would it make sense to allow a override of this with a getter on the class? 
That way we could offer the possibility of  specifying it in e.g. 'socos' for those cases where 'default locale' isn't actually what the user 'prefers'. I think it should still default thos ```locale.getdefaultlocale```. 

Of course a override only actually makes sense if it's used for available content etc, so I have no problem leaving further research of this for later!