type Query {
    "Find issue."
    issue(id: String!): Issue!
    "List issues."
    issues(filter: IssueFilter): [Issue!]!

    "Find item."
    item(id: String!): Item!
    "List items."
    items(filter: ItemFilter): [Item!]!
    "List item tags."
    itemTags: [String!]!

    "Find project."
    project(id: String!): Project!
    "List projects."
    projects(filter: ProjectFilter): [Project!]!

    "Check the user session."
    session: User
}