docs: function startMemMonitor() {
          checkInit();
          if (performance.memory !== void 0) {
              (function () {
                  var update = function update() {
                      data.addSample(Math.round(mem.usedJSHeapSize / (1024 * 1024)));
                      w.addResult(data.calc());
                      setTimeout(update, 30);
                  };
  
                  var data = new Data();
                  var w = new MonitorWidget("Memory", "MB", 1 /* HideMin */ | 4 /* HideMean */);
                  container.appendChild(w.element);
                  var mem = performance.memory;
  
                  update();
              })();
          }
      }