code: protected final String getMessageContentForTransfer(final boolean shouldEncodeMessage) throws StorageException {
          String result = null;
          if (this.messageType == QueueMessageType.RAW_STRING && shouldEncodeMessage) {
              result = Base64.encode(this.getMessageContentAsByte());
          }
          else {
              result = this.messageContent;
          }
  
          if (result != null && result.length() > QueueConstants.MAX_MESSAGE_SIZE) {
              throw new IllegalArgumentException(
                      String.format(SR.INVALID_MESSAGE_LENGTH, QueueConstants.MAX_MESSAGE_SIZE));
          }
  
          return result;
      }
docs: Gets the content of the message for transfer (internal use only).
  
  @return A <code>String</code> which contains the content of the message.
  
  @throws StorageException
  If a storage service error occurred.