query PullRequestForSha($owner: String!, $repo: String!, $sha: String!) {
  PullRequest {
    name
    title
    body
    id
    number
    author {
      person {
        chatId {
          screenName
        }
      }
    }
    repo(owner: $owner, name: $repo) @required {
      ...CoreRepoFieldsAndChannels
    }
    head(sha: $sha) @required {
      message
    }
    base {
      sha
      message
    }
  }
}