acceptDistributedTraceHeaders(transportType, headers) {
    incrementApiSupportMetric(this._metrics, 'acceptDistributedTraceHeaders')
    return this._transaction.acceptDistributedTraceHeaders(transportType, headers)
  }
Parsing incoming headers for use in a distributed trace.
W3C TraceContext format is preferred over the NewRelic DT format.
NewRelic DT format will be used if no `traceparent` header is found.

@param @param {string} [transportType='Unknown'] - The transport type that delivered the trace.
@param transportType
@param {object} headers - Headers to search for supported formats. Keys must be lowercase.