globalInstall = function(){
		factory(window.lazySizes);
		window.removeEventListener('lazyunveilread', globalInstall, true);
	}
Some versions of iOS (8.1-) do load the first candidate of a srcset candidate list, if width descriptors with the sizes attribute is used.
This tiny extension prevents this wasted download by creating a picture structure around the image.
Note: This extension is already included in the ls.respimg.js file.

Usage:

<img
	class="lazyload"
	data-sizes="auto"
	data-srcset="small.jpg 640px,
		medium.jpg 980w,
		large.jpg 1280w"
	/>