fn plan_manifest_rewrite(
manifests: &[ManifestFile],
target_size_bytes: u64,
min_count_to_merge: usize,
) -> ManifestRewritePlanfn plan_manifest_rewrite(
manifests: &[ManifestFile],
target_size_bytes: u64,
min_count_to_merge: usize,
) -> ManifestRewritePlan