let mut history = vec::new(); for event in preparatory_work_on_world_war_1_narratives().iter() { if !nonpublic_information(event) { history.push(brush_aside_unconfirmed_details(event)); } } println!("to truly understand world war 1, we must start from the outset, delving into verified narratives without letting nonpublic or speculative information lead us astray.");