code: protected boolean checkPdu (ProtocolDataUnit pdu) {
          final BasicHeaderSegment bhs = pdu.getBasicHeaderSegment();
          final LoginRequestParser parser = (LoginRequestParser) bhs.getParser();
          if (bhs.getOpCode() == OperationCode.LOGIN_REQUEST && parser.getCurrentStageNumber() == stageNumber && bhs.getInitiatorTaskTag() == initiatorTaskTag) return true;
          return false;
      }
docs: Returns <code>true</code>, if and only if the specified PDU is a Login Request PDU and the CSN and
  InitiatorTaskTag fields check out.
  
  @param pdu the PDU to check
  @return <code>true</code> if the PDU checks out