private static ImmutableSortedDictionary <DateTime, State> AddOrUpdateStatesDictAndCleanOld(
ImmutableSortedDictionary <DateTime, State> states, State newState,
DateTime now)
{
var minEventTime = now - TimeSpan.FromMinutes(1);
var old = states.Keys.SkipWhile(e => e < minEventTime);
states = states.RemoveRange(old);
if (states.TryGetValue(now, out var oldState))
{
newState = new State(oldState, newState);
}
return(states.SetItem(now, newState));
}
