syntax_data: {"ast_node_type":"other","tokens":[{"end":64,"kind":"keyword","start":0,"text":"ty::GenericArgKind::Type(ty)"}]}
source_snippet:                 ty::GenericArgKind::Type(ty) => self.add_ty(ty),
context_before:             match arg.kind() {
context_after:                 ty::GenericArgKind::Lifetime(lt) => self.add_region(lt),