// return eina_error
public static void eina_error_return()
{
test.ITesting obj = new test.Testing();
eina.Error expected = 42;
obj.SetErrorRet(expected);
eina.Error error = obj.ReturnsError();
Test.AssertEquals(expected, error);
expected = 0;
obj.SetErrorRet(expected);
error = obj.ReturnsError();
Test.AssertEquals(expected, error);
}