Function commits_from 

pub fn commits_from(
    root: CommitLogDir,
    offset: u64,
) -> Result<impl Iterator<Item = Result<StoredCommit, Traversal>>>

Obtain an iterator which traverses the commitlog located at the root directory starting from offset and yielding StoredCommits.

Starts the traversal without the upfront I/O imposed by Commitlog::open. See Commitlog::commits_from for more information.