How to get list of objects using an array in AWS App Sync?

The intention is to query a list of users using an array of User IDs passed into a contains filter. The schema below is my attempt at solving this, but the query does not return a list of users. Even passing only a single User ID results in an empty query result. This schema is being published to AWS AppSync.

Is it possible to query a list of users using an array of User IDs in AppSync?

schema.graphql

type User @model {
  id: ID!
  username: String!
  friends: [String]
}

type Query {
    getAllFriends(filter: ModelAllFriendsFilterInput): ModelGetAllFriends
}

type ModelGetAllFriends {
  items: [User]
}

input ModelAllFriendsFilterInput {
  id: ModelAllFriendsIDInput
}

input ModelAllFriendsIDInput {
  contains: [ID]
}

GraphQL Query:

query MyQuery {
  getAllFriends(filter: {id: {contains: "VALID-USER-ID-HERE"}}) {
    items {
      id
      username
    }
  }
}

Query result:

{
  "data": {
    "getAllFriends": null
  }
}