syntax_data: {"ast_node_type":"other","tokens":[{"end":56,"kind":"keyword","start":0,"text":"ty::ClauseKind::UnstableFeature(symbol)"}]}
source_snippet:             ty::ClauseKind::UnstableFeature(symbol) => {
context_before:             }
context_after:                 write!(p, "unstable feature: ")?;