docs: @View(name = "by_username", map = "function(doc) { if(doc.secretKey) { emit(doc.username, doc) } }")
      public CouchDbGoogleAuthenticatorAccount findOneByUsername(final String username) {
          val view = createQuery("by_username").key(username).limit(1);
          try {
              return db.queryView(view, CouchDbGoogleAuthenticatorAccount.class).stream().findFirst().orElse(null);
          } catch (final DocumentNotFoundException ignored) {
              return null;
          }
      }