_getTransportPayload (extraOpts) {
    return {
      apiKey: this._apiKey,
      apiSecret: this._apiSecret,
      authToken: this._authToken,
      company: this._company,
      transform: this._transform,
      ...extraOpts
    }
  }
Returns an arguments map ready to pass to a transport constructor

@param {object} extraOpts - options to pass to transport
@returns {object} payload