docs: @Override
  	public Response register(String CorpNum, Cashbill cashbill, String UserID)
  			throws PopbillException {
  		if (cashbill == null)
  			throw new PopbillException(-99999999, "현금영수증정보가 입력되지 않았습니다.");
  
  		String PostData = toJsonString(cashbill);
  
  		return httppost("/Cashbill",CorpNum, PostData,
  				UserID, Response.class);
  
  	}