/// <summary>Initializes the slot.</summary>
/// <param name="key">The key.</param>
/// <param name="value">The value.</param>
internal void InitSlot(RunStateKey key, object value)
{
var initialized = _stateSlots.TryAdd(key, value);
Code.AssertState(initialized, "Attempt to overwrite filled state slot.");
}
public object GetSlot(RunStateKey key, Func <object> valueFactory) => _stateSlots.GetOrAdd(key, _ => valueFactory());