docs: function(rirs) {
        var vacuumIRs = [];
        rirs.forEach(function(ir) {
          if (ir instanceof tr.e.rail.LoadInteractionRecord ||
              ir instanceof tr.e.rail.IdleInteractionRecord)
            vacuumIRs.push(ir);
        });
        if (vacuumIRs.length === 0)
          return;
  
        var allAssociatedEvents = tr.model.getAssociatedEvents(rirs);
        var unassociatedEvents = tr.model.getUnassociatedEvents(
            this.model, allAssociatedEvents);
  
        unassociatedEvents.forEach(function(event) {
          if (!(event instanceof tr.model.ThreadSlice))
            return;
  
          if (!event.isTopLevel)
            return;
  
          for (var iri = 0; iri < vacuumIRs.length; ++iri) {
            var ir = vacuumIRs[iri];
  
            if ((event.start >= ir.start) &&
                (event.start < ir.end)) {
              ir.associatedEvents.addEventSet(event.entireHierarchy);
              return;
            }
          }
        });
      }