public unsafe class TestSystem : JobComponentSystem
{
    private EntityQuery _query;
    private IReactionBuilder _reactions;
    private IReactionBuilder _burstReactions;
    private NativeObject<OnSelected> _onSelected;

    protected override void OnCreate()
    {
        SetupMethods();
        SetupBurstMethods();

        _query = GetEntityQuery(_reactions.QueryDesc, _burstReactions.QueryDesc);

        RequireForUpdate(_query);
    }

    private void SetupMethods()
    {
        _reactions = new ReactionBuilder<
            Delegate<OnMatchedEvent, MatchedEvent>,
            Delegate<OnPointerPressedEvent, PointerPressedEvent>,
            Delegate<DoSomethingElse, PointerPressedEvent>>();

        _reactions.Add<MatchedEvent, OnMatchedEvent>();

        // Test multiple methods triggered off the same component.
        _reactions.Add<PointerPressedEvent, OnPointerPressedEvent>();
        _reactions.Add<PointerPressedEvent, DoSomethingElse>();
    }

    private void SetupBurstMethods()
    {
        // Test burst and components passed to method being different from trigger component.
        _burstReactions = new ReactionBuilder<
            Delegate<OnSelected, Translation, BoardPosition, Rotation>>();

        _onSelected = _burstReactions.Add<SelectedElement, OnSelected>(new OnSelected
        {
            Count = 1000 // verify starting values passed in on creation make it through to the job.
        });
    }

    protected override JobHandle OnUpdate(JobHandle inputDeps)
    {
        // Verify burst jobs are working
        Debug.Log($"{_onSelected.Value.Count}");

        if (_onSelected.Value.Count > 1050)
        {
            // Test directly editing data jobs are using.
            _onSelected.Value.Count = 1000;
        }

        return JobHandle.CombineDependencies(
            _reactions.Job.Schedule(_query, inputDeps),
            _burstReactions.Job.Schedule(_query, inputDeps));
    }

    [BurstCompile]
    public struct OnSelected : IEntityHandler<Translation, BoardPosition, Rotation>
    {
        public void Invoke(Entity entity, ref Translation translation, ref BoardPosition boardPosition, ref Rotation rotation)
        {
            Count++;
        }
        public int Count;
    }

    public struct OnMatchedEvent : IEntityHandler<MatchedEvent>
    {
        public void Invoke(Entity entity, ref MatchedEvent component)
        {
            Debug.Log($"OnMatchedEvent Invoked {entity} Count={component.Count}");
            Count++;
        }

        public int Count;
    }

    public struct OnPointerPressedEvent : IEntityHandler<PointerPressedEvent>
    {
        public void Invoke(Entity entity, ref PointerPressedEvent component)
        {
            Debug.Log($"OnPointerPressedEvent Invoked {entity} Position={component.Position}");
            Count++;
        }
        public int Count;
    }

    public struct DoSomethingElse : IEntityHandler<PointerPressedEvent>
    {
        public void Invoke(Entity entity, ref PointerPressedEvent component)
        {
            Debug.Log($"DoSomethingElse Invoked {entity} Position={component.Position}");
            Count++;
        }
        public int Count;
    }
}