syntax_data: {"ast_node_type":"other","tokens":[{"end":54,"kind":"keyword","start":0,"text":"GenericArgKind::Lifetime(lt)"}]}
source_snippet:             GenericArgKind::Lifetime(lt) => lt.fmt(f),
context_before:         match self.kind() {
context_after:             GenericArgKind::Type(ty) => ty.fmt(f),