function _addRequest(transaction, entry, timeOrigin) {
  if (entry.responseEnd) {
    // It is possible that we are collecting these metrics when the page hasn't finished loading yet, for example when the HTML slowly streams in.
    // In this case, ie. when the document request hasn't finished yet, `entry.responseEnd` will be 0.
    // In order not to produce faulty spans, where the end timestamp is before the start timestamp, we will only collect
    // these spans when the responseEnd value is available. The backend (Relay) would drop the entire transaction if it contained faulty spans.
    utils$1._startChild(transaction, {
      op: 'browser',
      origin: 'auto.browser.browser.metrics',
      description: 'request',
      startTimestamp: timeOrigin + msToSec(entry.requestStart ),
      endTimestamp: timeOrigin + msToSec(entry.responseEnd ),
    });

    utils$1._startChild(transaction, {
      op: 'browser',
      origin: 'auto.browser.browser.metrics',
      description: 'response',
      startTimestamp: timeOrigin + msToSec(entry.responseStart ),
      endTimestamp: timeOrigin + msToSec(entry.responseEnd ),
    });
  }
}
Create request and response related spans