testing - NUnit How will I get two data sources for my single testcase -

i have test data in locationtestdata class

public static ienumerable validloc   {                 {             yield return new testcasedata("aaa", "qqqq"); //locationid , postal code                        }     }      public static ienumerable validpass     {                 {             yield return new testcasedata("bbbb", "wwww"); //locationid , postal code                        }     } 

and here test case

 [test, testcasesource(typeof(locationtestdata),"validloc")]         public void return(string value1, string value2, string value3, string value4)     {       } 

the error not enough arguments provided.

i have tried in way, no luck

[test, testcasesource(typeof(locationtestdata),"validloc")] [test, testcasesource(typeof(locationtestdata),"validpass")]          public void return(string value1, string value2, string value3, string value4)     {       } 

any ideas around?