should throw error when invalid input

saying i have
~~~
[user1]
name=bruce
age=a30
~~~

my struct
~~~
type user struct {
    Name string
    Age int
}
~~~
when i try to 
~~~
err = cfg.MapTo(u)
~~~
i expect an error is throwed out because `a30` is not a valid int value,  but actually go-ini didn't throw any error