<Proposal title="Test">
  <Observation>
    <Visit>
      <VisitGroup>
        <ParallelSequenceID>
          <Activity>
            <Exposure>
              <Detector>
                <base></base>
                <subarray></subarray>
                <exp_type></exp_type>
              </Detector>
            </Exposure>
          </Activity>
        </ParallelSequenceID>
      </VisitGroup>
    </Visit>
  </Observation>
</Proposal>
