setSelfLink method
Sets the URL where this Publication's RWPM manifest is served.
Implementation
void setSelfLink(String href) {
List<Link> list = _manifest.links.toList();
list.removeWhere((it) => it.rels.contains("self"));
list.add(Link(
href: href,
type: MediaType.readiumWebpubManifest.toString(),
rels: {"self"}));
_manifest.links = list;
}