'Retrieve the asset from this release with ``asset_id``.
:param int asset_id: ID of the Asset to retrieve
:returns: :class:`~github3.repos.release.Asset`'

def asset(self, asset_id):

    json = None
    if (int(asset_id) > 0):
        i = self._api.rfind(u'/')
        url = self._build_url(u'assets', str(asset_id), base_url=self._api[:i])
        json = self._json(self._get(url), 200)
    return self._instance_or_null(Asset, json)
