syntax_data: {"ast_node_type":"other","tokens":[{"end":56,"kind":"keyword","start":0,"text":"#[allow(rustc::potential_query_instability)]"}]}
source_snippet:             #[allow(rustc::potential_query_instability)]
context_before:             // that we insert data into doesn't depend on insertion order.
context_after:             let latest_ctxts = { mem::take(&mut *self.latest_ctxts.lock()) }.into_iter();