fn apply_block_empty_section_changes(
sections: &LightSectionReadCache<'_>,
light: &mut LightLayerEdit<'_>,
empty_sections: &[LightSectionEmptinessChange],
) -> usizefn apply_block_empty_section_changes(
sections: &LightSectionReadCache<'_>,
light: &mut LightLayerEdit<'_>,
empty_sections: &[LightSectionEmptinessChange],
) -> usize