@Override
  public int hashCode() {
    int result = id;
    result = 31 * result + (int) (expirationDate ^ (expirationDate >>> 32));
    result = 31 * result + ((secret == null) ? 0 : Arrays.hashCode(secret.getEncoded()));
    return result;
  }
Represents a secret key used for signing and verifying authentication tokens by
{@link AuthenticationTokenSecretManager}.
hbase-server/src/main/java/org/apache/hadoop/hbase/security/token/AuthenticationKey.java