You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: iterator.rs
    path of file: ./repos/sled/src/pagecache
    
    the code of the file until where you have to start completion: use std::{collections::BTreeMap, io};

use super::{
    pread_exact_or_eof, read_message, read_segment_header, BasedBuf, DiskPtr,
    LogKind, LogOffset, LogRead, Lsn, SegmentHeader, SegmentNumber,
    MAX_MSG_HEADER_LEN, SEG_HEADER_LEN,
};
use crate::
    
const fn valid_entry_offset(lid: LogOffset, segment_len: usize) -> bool {
    let seg_start = lid / segment_len as LogOffset * segment_len as LogOffset;

    let max_lid =
        seg_start + segment_len as LogOffset - MAX_MSG_HEADER_LEN as LogOffset;

    let min_lid = seg_start + SEG_HEADER_LEN as LogOffset;

    lid >= min_lid && lid <= max_lid
}