constructor(attributes, customAttributes) {
    this.customAttributes = customAttributes
    this.attributes = attributes
    this.intrinsics = new SpanIntrinsics()

    if (attributes.host) {
      this.addAttribute(SERVER_ADDRESS, attributes.host)
      attributes.host = null
    }

    if (attributes.port) {
      this.addAttribute('server.port', attributes.port, true)
      attributes.port = null
    }
  }
General span event class.

Do not construct directly, instead use one of the static `from*` methods such
as `SpanEvent.fromSegment`.

@private
@class