function doWorkInSegment({ agent, api, segmentName }, cb) {
  api.startSegment(segmentName, true, () => {
    const segment = agent.tracer.getSegment()
    cb(segment)
  })
}
Creates a segment and forces the name for easier assertion.

@param {object} params to function
@param {object} params.api agent api
@param {object} params.agent agent instance
@param {string} params.segmentName name of segment to force
@param {function} cb function to call within segment creation and passes newly created segment