syntax_data: {"ast_node_type":"other","tokens":[{"end":50,"kind":"keyword","start":0,"text":"GenericArgKind::Type(ty)"}]}
source_snippet:             GenericArgKind::Type(ty) => ty.fmt(f),
context_before:             GenericArgKind::Lifetime(lt) => lt.fmt(f),
context_after:             GenericArgKind::Const(ct) => ct.fmt(f),