code: public boolean execute (ProtocolDataUnit pdu) throws OperationNotSupportedException , IOException , InterruptedException , InternetSCSIException , DigestException , SettingsException {
          throw new OperationNotSupportedException();
      }
docs: Throws an {@link OperationNotSupportedException} unless overwritten.
  
  @param pdu the first PDU to be processes as part of the phase
  @return <code>true</code> if and only if the phase was completed successfully
  @throws OperationNotSupportedException if the method is not overwritten
  @throws IOException if an I/O error occurs
  @throws InterruptedException if the current Thread is interrupted
  @throws InternetSCSIException if a iSCSI protocol violation is detected
  @throws DigestException if a PDU digest error is detected
  @throws SettingsException if the target tries to access a parameter that has not been declared or negotiated and
  that has no default value