Function extract_clusters_for_cpu_clustering 

pub fn extract_clusters_for_cpu_clustering(
    commands: Commands<'_, '_>,
    views: Extract<'_, '_, Query<'_, '_, (RenderEntity, &Clusters, &Camera)>>,
    mapper: Extract<'_, '_, Query<'_, '_, (Option<&RenderEntity>, (Has<PointLight>, Has<SpotLight>, Has<EnvironmentMapLight>, Has<IrradianceVolume>, Has<ClusteredDecal>)), Or<(With<PointLight>, With<SpotLight>, With<EnvironmentMapLight>, With<IrradianceVolume>, With<ClusteredDecal>)>>>,
    global_cluster_settings: Extract<'_, '_, Res<'_, GlobalClusterSettings>>,
)

Extracts the clusters that the CPU produced into the render world.