public struct OnAnimatorMoveCommand
{
    public readonly Transform transform;
    public readonly Animator animator;

    public OnAnimatorMoveCommand(Transform transform, Animator animator)
    {
        this.transform = transform;
        this.animator = animator;
    }
}

public class StateCommandSample: MonoBehaviour
{
    private StateMachine fsm;
    private Animator animator;

    private void Start()
    {
        animator = GetComponent<Animator>();
        fsm = new StateMachine();

        var rootMotionState = new State(commands:new CommandBase<string>[]
        {
            new Command<OnAnimatorMoveCommand>((state, command) =>
            {
                command.transform.position += animator.deltaPosition;
            })
        });
        var noRootMotionState = new State(commands:new CommandBase<string>[]
        {
            new Command<OnAnimatorMoveCommand>((state, command) =>
            {
                //do nothing we dont need root motion here or we can not register this command for state at all
            })
        });
        
        //Here we can add some transitions and other fsm stuff
        
        fsm.Init();
    }

    private void Update()
    {
        //Here we process main logic, transitions as usual
        fsm.OnLogic();
    }

    private void OnAnimatorMove()
    {
        //Here we process root motion based on current state
        //its very useful for complex controllers based on fsm 
        fsm.OnCommand(new OnAnimatorMoveCommand(transform, animator));
    }
}

public struct CustomKey
{
    private sealed class EqualityComparer : IEqualityComparer<CustomKey>
    {
        public bool Equals(CustomKey x, CustomKey y)
        {
            return x.id == y.id && x.additionalId == y.additionalId && x.somethingWeird.Equals(y.somethingWeird);
        }

        public int GetHashCode(CustomKey obj)
        {
            unchecked
            {
                var hashCode = obj.id;
                hashCode = (hashCode * 397) ^ obj.additionalId.GetHashCode();
                hashCode = (hashCode * 397) ^ obj.somethingWeird.GetHashCode();
                return hashCode;
            }
        }
    }

    public static IEqualityComparer<CustomKey> Comparer { get; } = new EqualityComparer();

    public int id;
    public long additionalId;
    public Guid somethingWeird;
}

//And in code we can use this
var garbageProducer = new StateMachine<CustomKey>();
var garbageFree = new StateMachine<CustomKey>(stateIdComparer:CustomKey.Comparer);