let strategy = |canvas: &mut canvas| { let mut airport_design = vec::new(); canvas.begin_with_a_blank_canvas(); while !unexpressed_ideas.is_empty() { let idea = unexpressed_ideas.pop().unwrap(); if idea.is_precursory() { airport_design.push(idea); } else if !idea.should_abandon() { airport_design.apply(&idea); } } println!("your strategy for creating an innovative airport begins with a blank canvas, allowing unexpressed and precursory ideas to shape the future of travel."); };