: Could not find a matching Java operation for WSDD operation "sum"

I have my java class with the webservice        package com.test;

    import javax.jws.WebMethod;
    import javax.jws.WebParam;
    import javax.jws.WebService;

@WebService(serviceName = "HolaMundo")
public class HolaMundo {

@WebMethod(operationName = "hello")
 public String hello(@WebParam(name = "name") String txt) {
 return "Hello " + txt + " !";
 }

@WebMethod(operationName = "Suma")
 public String Suma(@WebParam(name = "num1") int numero, @WebParam(name = "num2") int num  ) {
 return "Suma total es "+(numero+num);
 }


}

When looking for my wsdl I get the error of the title. Any solution?