constructor(opts, agent) {
    const { metrics, collector, harvester } = agent
    opts = opts || {}
    opts.periodMs = opts.periodMs ? opts.periodMs : 1000
    opts.limit = opts.limit ? opts.limit : 10000
    opts.method = opts.method || 'span_event_data'

    super(opts, collector, harvester)

    this.stream = opts.span_streamer
    this.metrics = metrics
    this.started = false
    this.isStream = true
  }
Handles streaming of spans to the New Relic data collector.