#import #import callback FunctionStringCallback = undefined (DOMString data); // https://html.spec.whatwg.org/multipage/dnd.html#datatransferitem [Exposed=Window] interface DataTransferItem { readonly attribute DOMString kind; readonly attribute DOMString type; undefined getAsString(FunctionStringCallback? _callback); File? getAsFile(); // https://wicg.github.io/entries-api/#dom-datatransferitem-webkitgetasentry FileSystemEntry? webkitGetAsEntry(); };