在blueimp-jQuery-File-Upload中，如何在回调函数中获取fileupload初始化的属性值

Question

在blueimp-jQuery-File-Upload中，初始化fileupload的时候设置了maxNumberOfFiles，在回调函数fileuploadchange中如何访问maxNumberOfFiles的值？

var popup = $('#upload-file-dialog2').addClass('fixed-upload-file-dialog');;
var popup_height = '200px';
popup.css({'height': popup_height}).data('height', popup_height);   
popup.fileupload({
    fileInput: $('#upload-file2 input'),
    paramName: 'file',
    // customize it for 'done'
    getFilesFromResponse: function (data) {
        if (data.result) {
            return data.result;
        }
    },
    autoUpload:true,
    {% if max_upload_file_size %}
    maxFileSize: {{ max_upload_file_size }}, // in bytes
    {% endif %}
    maxNumberOfFiles: 9,
    sequentialUploads: true
})
.bind('fileuploadchange',function(e,data){
    if(data.files.length>9){
            $('#warning-popup').modal({appendTo:'#main'});
            $('#simplemodal-container').css({'height':'auto'});
            $('#warning-con').html('<h3>' + "{% trans "提示" %}" + '</h3><p>' + "{% trans "添加的文件过多，单次窗口最多添加9个" %}" + '</p>');

        return false;
    }
})