Function _bench_parquet_metadata_bincode_size 

pub fn _bench_parquet_metadata_bincode_size(
    path: &str,
    projection: Option<Vec<String>>,
    predicate: Vec<String>,
) -> PyResult<usize>

Decode a parquet footer, optionally apply FileMetadata::pruned, then bincode-encode and return the byte length of the wire form.

Exposed for out-of-tree measurement of the IR-plan-borne metadata wire form (the bincode(FileMetadata) blob shipped to workers in distributed execution); no caller in py-polars itself.

projection = None ⇒ encode the full FileMetadata. projection = Some(cols) ⇒ apply pruned(cols, predicate). Local files only.