            }
            },
            {
                type: 'graph',
                name: 'MEM',
                range: 300,
                value: performance.memory,
                callback: (value, item) => {
                    // console.log('MEM callback:', value);

                    const mem = value.usedJSHeapSize / Math.pow(1000, 2);

                    item.update(mem);
                    item.setValue(mem);

                    // The return value is passed back in the next frame
     