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