src/vs/workbench/browser/dnd.ts/toggleDropEffect
export function toggleDropEffect(dataTransfer: DataTransfer | null, dropEffect: 'none' | 'copy' | 'link' | 'move', shouldHaveIt: boolean) {
	if (!dataTransfer) {
		return;
	}

	dataTransfer.dropEffect = shouldHaveIt ? dropEffect : 'none';
}