docs: function verify (token, options) {
    options = options || {}
    options.issuer = options.issuer || this.issuer
    options.client_id = options.client_id || this.client_id
    options.client_secret = options.client_secret || this.client_secret
    options.scope = options.scope || this.scope
    options.key = options.key || this.jwks.sig
  
    return new Promise(function (resolve, reject) {
      AccessToken.verify(token, options, function (err, claims) {
        if (err) { return reject(err) }
        resolve(claims)
      })
    })
  }