pub fn read_pages_locations<R: ChunkReader>(
    reader: &R,
    chunks: &[ColumnChunkMetaData],
) -> Result<Vec<Vec<PageLocation>>, ParquetError> {
    let fetch = chunks
        .iter()
        .fold(None, |range, c| acc_range(range, c.offset_index_range()));

    let fetch = match fetch {
        Some(r) => r,
        None => return Ok(vec![]),
    };

    let bytes = reader.get_bytes(fetch.start as _, fetch.end - fetch.start)?;
    let get = |r: Range<usize>| &bytes[(r.start - fetch.start)..(r.end - fetch.start)];

    chunks
        .iter()
        .map(|c| match c.offset_index_range() {
            Some(r) => decode_offset_index(get(r)),
            None => Err(general_err!("missing offset index")),
        })
        .collect()
}