@Override
  public DelegationTokenInformation getToken(DelegationTokenIdentifier tokenIdentifier) {
    DelegationTokenInformation result = tokens.get(tokenIdentifier);
    LOG.trace("getToken: tokenIdentifier = {}, result = {}", tokenIdentifier, result);
    return result;
  }
Default in-memory token store implementation.
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/security/MemoryTokenStore.java