Github username from known email - possible?

Anyone know how to user the github API to get a username from a known email address?
Playing with https://developer.github.com/v4/explorer/ — not having any luck.

I hoped something like this would work…

{
  search(query: "<my-domain>+in:email", type: USER, first:0) {
    nodes {
      ... on User {
        id
        email
        login
        name
      }
    }
  }
}

Thanks for any info!