nested explicit resolver not invoked

This may be a request for clarification rather than a bug report, but I have a schema similar to this:
```
type Foo {
id: ID!
bar: Bar! @goField(forceResolver: true)
}

type Bar {
baz: Baz! @goField(forceResolver: true)
}

type Baz {
value: Value! @goField(forceResolver: true)
}

type Query {
queryFoos(...): [Foo!]!
}
```
and then a unit test with a query that requests all the fields in this little example.

gql geneartes all those resolvers without problems, but the resolver for `value` is never invoked and my test fails with
```
"the requested element is null which the schema does not allow"
```
Am I missing a step or is there a limit to how deep these nested resolvers will be invoked?

Thanks