Used to retrieve leaderboard entries relative a user's entry. If there are not enough entries in the leaderboard before or after the user's entry, Steam will adjust the range to try to return the number of entries requested. For example, if the user is #1 on the leaderboard and start is set to -2, end is set to 2, Steam will return the first 5 entries in the leaderboard. If The current user has no entry, this will return null.