public function addRel($blog_id, $role_id)
{
Laralum::permissionToAccess('laralum.blogs.access');
$rel = Blog_Role::whereBlog_idAndRole_id($blog_id, $role_id)->first();
if (!$rel) {
$rel = new Blog_Role();
$rel->blog_id = $blog_id;
$rel->role_id = $role_id;
$rel->save();
}
}