How to get End Simulation EntityCommandBuffer System in ECS 1.0?

I ask ECS questions but I always got an old version answer of ECS.
For example, World.GetOrCreateSystem() is not the right way in ECS 1.0

private EndSimulationEntityCommandBufferSystem endSimulationEcbSystem;
public void OnCreate(ref SystemState state)
    endSimulationEcbSystem = World.GetOrCreateSystem();
    // ...

This is how you create EndSimulation EntityCommandBuffer @ com.unity.entities 1.0

public void OnCreate ( ref SystemState state )
    EntityCommandBuffer ecb = SystemAPI
        .CreateCommandBuffer( state.WorldUnmanaged );
1 Like