// init all
            larvitar.initializeImageLoader();
            larvitar.registerNRRDImageLoader();
            larvitar.initializeCSTools();
            larvitar.store.initialize();
            larvitar.store.addViewport("viewer");

            createFile("example.nrrd", function (nrrd_file) {
              let reader = new FileReader();
              reader.readAsArrayBuffer(nrrd_file);
              reader.onload = function () {
                let volume = larvitar.importNRRDImage(reader.result);
                let serie = larvitar.buildNrrdImage(volume, "1234", {});
                larvitar.renderImage(serie, "viewer");
                larvitar.addDefaultTools();
                larvitar.setToolActive("Wwwc");
              };
            });

            async function createFile(fileName, callback) {
              let response = await fetch("./demo/" + fileName);
              let data = await response.blob();
              let file = new File([data], fileName);
              callback(file);
            }