How to animate a link into a model

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Hi all,

I have a model (not an actor) that has links and joint. Let's say I want to put an animation on a special link, showing that a motor is spinning (without changing the velocity of a joint or redefining the model into an actor)

Is it possible to attach an actor or an animation (for example taken from a .dae file) to a link in a model (programmatically if needed)? In this tutorial, it is said that "There can't be models nested inside actors". Is it true the other way? I tried to add an actor inside a model in a SDF file but it doesn't seem to be possible or am I wrong?