Add promise to entity

How can i add promise to an entity similar to that of model.

I want to perform events after the entity is loaded,Is that possible.

**I shared a sample ****Sandcastle **link for reference.I have loaded a model with promise, similarly can i add an entity.

Unfortunately, entities don’t have a ready promise in the same way primitives do, because entities can be dynamic and may load/reload things throughout its lifetime. Functions like viewer.flyTo(entity) will automatically wait for the entity to finish loading before initiating. They do this by checking every frame if the entity is ready.

It involves some private classes, but you can see how this logic is computed here:

There’s also some discussion here about exposing this kind of property for entities: