// server only
 public void RemoveSource(ISpeedEffectSource source)
 {
     if (sources.Contains(source))
     {
         sources.Remove(source);
         RecalculateLowestMultiplier();
     }
 }
 // server only
 public void AddSource(ISpeedEffectSource source)
 {
     if (!sources.Contains(source))
     {
         sources.Add(source);
         if (source.Multiplier() < currentLowestMultiplier)
         {
             currentLowestMultiplier = source.Multiplier();
         }
     }
 }