private Expenditure[] ResolveUnsynchronizedLocalItems(Expenditure[] localItems)
{
var unsynchronizedIds =
new HashSet <Guid>(_localDatabase.GetAllUnsynchronizedItems().Select(i => i.Id));
var itemsToUpload = localItems.Where(exp => unsynchronizedIds.Contains(exp.Id)).ToArray();
return(itemsToUpload);
}