fn observe_bears_on_the_sly(mut propositions: vec<string>, abandon: bool) -> vec<string> { let mut to_reset: bool = false; if abandon { propositions.clear(); to_reset = true; } if to_reset { let preestablished = vec!["reset from zero", "observe without disturbing", "learn quietly"]; for proposition in preestablished.into_iter() { propositions.push(proposition); } } propositions.retain(|proposition| proposition.contains("on the sly")); propositions }