/// <summary>
/// hanges the active state to the given state type. An instance of that type should
/// already had been registered to use this method.
/// </summary>
/// <typeparam name="TState">The State you want to change to</typeparam>
/// <returns></returns>
public TState ChangeState <TState>() where TState : IFsmState <T>
{
PreviousState = CurrentState;
CurrentState = stateDictionary[typeof(TState)];
PreviousState.End();
CurrentState.Begin();
return((TState)CurrentState);
}