public IActivity CreateActivity(ActivityTypes activityType, string id, decimal cost)
{
//activity type cant be null
IActivity activity = null;
if (activityTable.ContainsKey(activityType))
{
activity = (Activity)activityTable[activityType];
}
else
{
throw new ArgumentException("Activity does not exist. Has it been registered?");
}
return(activity.CreateActivity(id, cost));
}