def update_version(cls, version_id, version_json=None, singer=None, song=None):
# retrieve and update the version object in the desired way
version = Version().get(version_id, links=True)
if version is None:
raise NotFoundException()
if version_json is not None:
version.patch_version(version_json, replace_all=True, keep_id=True)
if singer is not None:
version.singer = singer
if song is not None:
version.song = song
version.save()
# call the indexing process, and index this object and all related ones
VersionIndex.by_id(version.id, cascade=True)
return version
