{"ast_node_type":"other","tokens":[{"end":65,"kind":"keyword","start":0,"text":"RegionConstraintCollector(region_constraints::UndoLog<'tcx>),"}]}
    RegionConstraintCollector(region_constraints::UndoLog<'tcx>),
    FloatUnificationTable(sv::UndoLog<ut::Delegate<ty::FloatVid>>),
    RegionUnificationTable(sv::UndoLog<ut::Delegate<RegionVidKey<'tcx>>>),