Может кто-нибудь объяснить эту альтернативу try / catch в bash?

Я использовал в остальном вызов

** Date Variable: Created **

var call = $.ajax({
            url: "../_api/Web/Lists/GetByTitle('NewUser')/items?$filter=(Created%20ge%20datetime'"+FromDate+"')%20and%20(Created%20le%20datetime'"+ToDate+"' and Title eq '"+epf+"' )&$top=5000",
            type: "GET",
            dataType: "json",
            headers: {
                Accept: "application/json;odata=verbose"
            }

            });

  call.done(function (data,textStatus, jqXHR){
        $('#example').dataTable({
            "bDestroy": true,
            "bProcessing": true,
            "aaData": data.d.results,
            "aLengthMenu" : [
             [50,100],
             [50,100]
            ],
             dom: 'Bfrtip',
            buttons: [
                'copy', 'csv', 'excel'
            ],

            "aoColumnDefs": [{ "bVisible": false  }],
            "aoColumns": [
                { "mData": "ID" },
                { "mData": "Title" },
                { "mData": "EmployeeName" },
                { "mData": "Department1" },
                { "mData": "ServicingAt" },
                { "mData": "TestField" }, 
                { "mData": "BranchCode" },   
                { "mData": "Created" ,"render": function (data, type, row) {
        data = moment(data).format('DD MMM YYYY');
        return data;
    }