selec2 ajax cache

$("#selIUT").select2({
            cacheDataSource: [],
            placeholder: "Please enter the name",
            query: function(query) {
                self = this;
                var key = query.term;
                var cachedData = self.cacheDataSource[key];

                if(cachedData) {
                    query.callback({results: cachedData.result});
                    return;
                } else {
                    $.ajax({
                      url: '/ajax/suggest/',
                      data: { q : query.term },
                      dataType: 'json',
                      type: 'GET',
                      success: function(data) {
                        self.cacheDataSource[key] = data;
                        query.callback({results: data.result});
                      }
                    })
                }
            },
            width: '250px',
            formatResult: formatResult, 
            formatSelection: formatSelection, 
            dropdownCssClass: "bigdrop", 
            escapeMarkup: function (m) { return m; } 
        });