@Override
  public void close() throws IOException {
    enabled = false;
  }
Fetches the key associated with the pair of AccountId and ContainerId. {@link SingleKeyManagementService} returns
the default key for all {@link #getKey(RestRequest, short, short)}}
@param restRequest the {@link RestRequest} to use
@param accountId refers to the id of the {@link Account} for which key is expected
@param containerId refers to the id of the {@link Container} for which key is expected
@return {@link SecretKeySpec} the key associated with the accountId and containerId
ambry-router/src/main/java/com/github/ambry/router/SingleKeyManagementService.java