code: @Override
  	public Response sendSMS(String CorpNum, int ItemCode, String MgtKey,
  			String Sender, String Receiver, String Contents, String UserID)
  			throws PopbillException {
  		if (MgtKey == null || MgtKey.isEmpty())
  			throw new PopbillException(-99999999, "관리번호가 입력되지 않았습니다.");
  		
  		ResendRequest request = new ResendRequest();
  		
  		request.sender = Sender;
  		request.receiver = Receiver;
  		request.contents = Contents;
  		
  		String PostData = toJsonString(request);
  		
  		return httppost("/Statement/" + ItemCode + "/" + MgtKey, CorpNum, PostData, 
  				UserID, "SMS", Response.class);
  	}
docs: /* (non-Javadoc)
  @see com.popbill.api.StatementService#sendSMS(java.lang.String, java.number.Integer, java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String)