Function render_through 

pub async fn render_through<B: Backend>(
    graph: &Graph,
    target: &str,
    config: RenderConfig,
    store: &Store<B>,
) -> Result<Render, EngineError>

render through store, from the root down: a node the store answers stands as its samples, and nothing under it is typed, planned or looked up. What the rest computes is staged beside the store as the render drops it; only persist writes the store.