Implementing a Race Event Bus

We are going to implement the Race Event Bus in two easy steps:

1. To start, we need to expose the specific race event types that we support, which we will do with the following enum:

namespace Chapter.EventBus
{
    public enum RaceEventType
    {
        COUNTDOWN, START, RESTART, PAUSE, STOP, FINISH, QUIT
    }
}

It's important to note that the preceding enum values represent specific events outlining the stages of a race, from start to finish. So we are restricting ourselves to handling events with just a global scope.

2. The next part is the core component of the pattern, the actual game event bus class, which we will call RaceEventBus, to be more domain-specific in the naming convention of our classes:

using UnityEngine.Events;
using System.Collections.Generic;

namespace Chapter.EventBus
{
    public class RaceEventBus
    {
        private static readonly 
            IDictionary<RaceEventType, UnityEvent> 
            Events = new Dictionary<RaceEventType...