syntax_data: {"ast_node_type":"other","tokens":[{"end":70,"kind":"keyword","start":0,"text":"$(#[allow(unused_lifetimes)]"}]}
source_snippet:         $(#[allow(unused_lifetimes)] impl<'tcx> fmt::Display for $ty {
context_before:         // Some of the $ty arguments may not actually use 'tcx
context_after:             fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {