code: function Strategy (options, verify) {
    if (typeof options === 'function') {
      verify = options
      options = {}
    } else {
      if (options && options.log) {
        log = options.log
      }
    }
    if (!verify) {
      throw new Error('apikey authentication strategy requires a verify function')
    }
  
    passport.Strategy.call(this)
  
    this._apiKeyHeader = options.apiKeyHeader || 'api_key'
    this.name = 'apikey'
    this._verify = verify
    this._passReqToCallback = true
  }
docs: Creates an instance of `Strategy` checking api keys.