this.importing_=true;const importTask=new tr.b.Task(function prepareImport(){progressMeter.update('I will now import your traces for you...');},this);let lastTask=importTask;const importers=[];function addImportStage(title,callback){lastTask=lastTask.after(()=>progressMeter.update(title));lastTask.updatesUi=true;lastTask=lastTask.after(callback);}