Alex

| Q | A | ------------- | --- | Is bugfix? | yes | New feature? | no | Breaks BC? | no | Tests pass? | yes

Fix NPE in argument binder

2

In case of collection-argument with nullable items. Passing null items in collection-argument causes NPE in `org.springframework.graphql.data.GraphQlArgumentBinder#createCollection`: `Cannot invoke "Object.getClass()" because "rawValue" is null`. Test case: Schema: ```GraphQL type Query {...

Hi. https://github.com/Workiva/go-datastructures/blob/6e483a429c7b8d45d5487bcad780d0caa3a82146/cache/cache.go#L156 `c.keyList.Back()` returns `nil` if the list is empty.