Why listening cornerstoneimageloadprogress events, the callback function parameters of the event. The detail of the toal and percentComplete for undefined

[zhengdechang1]

Why listening cornerstoneimageloadprogress events, the callback function parameters of the event. The detail of the toal and percentComplete for undefined

my code
//cacha image
cornerState.leftStack.imageIds.map((imageId, index) =>
cornerstone.loadAndCacheImage(imageId).then((res) => {
// console.log(res, index)
})
)

// addEventListener
cornerstone.events.addEventListener(
'cornerstoneimageloadprogress',
function (event) {
const eventData = event.detail
console.log(eventData, 'eventData: ')
}
)

//result