Function bound 

pub fn bound<'a>(
    lines: impl IntoIterator<Item = &'a str>,
    now: i64,
) -> (Vec<&'a str>, usize)

What the log keeps of lines (its lines in order) at now: none past TTL_MS (with steer.rs SLACK_MS) or without an ms, and of each member’s lines (by the node a line names) of each Class the newest while they fit MEMBER_BYTES. Newest by stamp, then by the line itself, so every node holding the same lines keeps the same whatever order they arrived in; a node’s lines for its own sessions have classes of their own, so its peers, which never hold them, keep what it keeps of the lines that travel. The kept lines stay byte for byte, in their order. Returns them and how many the bytes bound cut. send and the mesh (borg-mesh sync.rs store_lines) bound the log by it alone.