lib/Lightbox.js
function normalizeSourceSet(data) {
	var sourceSet = data.srcSet || data.srcset;

	if (Array.isArray(sourceSet)) {
		return sourceSet.join();
	}

	return sourceSet;
}
function normalizeSourceSet(data) {
	var sourceSet = data.srcSet || data.srcset;

	if (Array.isArray(sourceSet)) {
		return sourceSet.join();
	}

	return sourceSet;
}
function normalizeSourceSet ( data ) { var sourceSet = data . srcSet || data . srcset ; if ( Array . isArray ( sourceSet ) ) { return sourceSet . join ( ) ; } return sourceSet ; }
consumers sometimes provide incorrect type or casing
consumers sometimes provide incorrect type or casing