private static void ValidatePlayerRanks(IList<PlayerRank> playerRanks)
{
if (playerRanks.Count > FIBONACCI_N_PLUS_2.Count)
{
throw new ArgumentException(EXCEPTION_MESSAGE_CANNOT_EXCEED_MAX_PLAYERS);
}
if (playerRanks.GroupBy(x => x.PlayerId).Count(y => y.Count() > 1) > 0)
{
throw new ArgumentException(string.Format(EXCEPTION_MESSAGE_DUPLICATE_PLAYER));
}
}