{"ast_node_type":"import","tokens":[{"end":87,"kind":"keyword","start":0,"text":"//"}]}
                    // uses the span, so this doesn't cause any problems at the moment.
                    // for performances reasons. The error reporting code used by NLL only
                    Some(ObligationCauseCode::WhereClause(CRATE_DEF_ID.to_def_id(), predicate_span))