Function advance 

fn advance(
    st: &mut State,
    procs: Vec<ProcInfo>,
    inputs: &Inputs,
    now: Instant,
    cmdline: &dyn Fn(ProcKey) -> Option<String>,
) -> Sampled

Measure: group the table, take every process’s and task account’s rate since the previous measurement, and remember sticky membership. cmdline reads a process’s command line, for labelling AgentMux’s own processes only (tower_agentmux).