{"ast_node_type":"other","tokens":[{"end":99,"kind":"keyword","start":0,"text":"///"}]}
    /// Given `T: Trait` predicate it returns `T: !Trait` and given `T: !Trait` returns `T: Trait`.
    ///
    pub fn flip_polarity(&self, tcx: TyCtxt<'tcx>) -> Option<PredicateObligation<'tcx>> {