docs: function Client (opts) {
    // update client instance and config
    // with overrides from opts.
    _.extend(this, {
      Saver: require('./saver').Saver
    }, opts)
  
    config.extend(opts)
  
    // allow sqs to be overridden
    // in tests.
    if (opts && opts.sqs) {
      this.sqs = opts.sqs
      delete opts.sqs
    } else {
      this.sqs = new aws.SQS({
        accessKeyId: config.get('awsKey'),
        secretAccessKey: config.get('awsSecret'),
        region: config.get('awsRegion')
      })
    }
  
    config.set('sqsQueueUrl', this.sqs.endpoint.protocol + '//' + this.sqs.endpoint.hostname + '/' + config.get('sqsQueue'))
  }