/// Adds a new child diagnostic message to `self` with the level
/// identified by this method's name with the given `spans` and
/// `message`.
#[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
pub fn $spanned<S, T>(mut self, spans: S, message: T) -> Diagnostic
/// Adds a new child diagnostic message to `self` with the level
/// identified by this method's name with the given `spans` and
/// `message`.
#[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
pub fn $spanned<S, T>(mut self, spans: S, message: T) -> Diagnostic