type Mutation {
  addPost(input: PostInput!): AddResult!
  addComment(input: CommentInput!): AddResult!
}

input PostInput {
  title: String!
  author: String!
  contents: String!
  allowComments: Boolean! = true
}

input CommentInput {
  parentPostId: ID
  parentCommentId: ID
  author: String!
  contents: String!
}

type AddResult {
  itemId: ID!
}