syntax_data: {"ast_node_type":"other","tokens":[{"end":67,"kind":"keyword","start":0,"text":"ty::Alias(ty::Opaque,"}]}
source_snippet:         ty::Alias(ty::Opaque, ty::AliasTy { def_id: def, .. }) => {
context_before:         // FIXME: support adding the attribute to TAITs
context_after:             let mut has_emitted = false;