in poc/src/commands.rs [158:168]
fn root_hash(parts: Vec<&str>) -> Option<DirectoryCommand> {
let mut epoch = None;
if parts.len() > 1 {
if let Ok(a) = parts[1].parse::<u64>() {
epoch = Some(a);
}
}
let cmd = DirectoryCommand::RootHash(epoch);
Some(cmd)
}