Function plan_apply 

pub fn plan_apply(
    platform: &str,
    service: Option<&str>,
    http_proxy: Option<&str>,
    https_proxy: Option<&str>,
    socks_proxy: Option<&str>,
    no_proxy: Option<&str>,
    current_settings: Option<&SystemProxySettings>,
) -> ApplyPlan

Create an apply plan without executing it (dry-run).