docs: @View(name = "by_username", map = "function(doc) { if(doc.publicId && doc.username) {emit(doc.username, doc)}}")
      public YubiKeyAccount findByUsername(final String uid) {
          val view = createQuery("by_username").key(uid).limit(1).includeDocs(true);
          return db.queryView(view, CouchDbYubiKeyAccount.class).stream().findFirst().orElse(null);
      }