code: @Override
      public void destroy()
      {
          this.externalProperties = null;
          Object connection = getConnectionPoolOrConnection();
  
          if (connection != null)
          {
              ((TransportClient) connection).close();
  
          }
      }
docs: /*
  (non-Javadoc)
  
  @see com.impetus.kundera.loader.ClientLifeCycleManager#destroy()