/**
  * Writes the stack trace of exceptions encountered by the {@link DataSubscriber} to the error
  * stream.
  */
 @Override
 public void exceptionEncountered(MessageEvent evt) {
   if (m_errorStream != null) {
     evt.getException().printStackTrace(m_errorStream);
     m_errorStream.println();
   }
 }
 /**
  * Writes the message received when the {@link DataSubscriber}'s connection is terminated to the
  * error stream.
  */
 @Override
 public void connectionTerminated(MessageEvent evt) {
   if (m_errorStream != null) {
     m_errorStream.println(evt.getMessage());
     m_errorStream.println();
   }
 }
 /** Writes status messages from the {@link DataSubscriber} to the output stream. */
 @Override
 public void statusMessageReceived(MessageEvent evt) {
   m_outputStream.println(evt.getMessage());
   m_outputStream.println();
 }