Function stateless 

fn stateless(keyed: &Keyed, ident: &str) -> String

The name format 2 gives an element format 1 named ident when the file here does not say otherwise: format 1 named it by itself (by empty), and its own id, else the id derived from it, names it; by its id: that id; by other fields (a session by its start, task and project): the id derived from them, the one written into it when a device took format 2.