/**
* Prepare an experiment for this session.
*
* @return string
*/
protected function nextExperiment($experiment = null)
{
// Verify that the experiments are in the database.
$this->checkExperiments();
if ($experiment) {
$experiment = Experiment::active()->findOrfail($experiment);
} else {
$experiment = Experiment::active()->orderBy('visitors', 'asc')->firstOrFail();
}
$this->session->set('experiment', $experiment->name);
// Since there is an ongoing experiment, increase the pageviews.
// This will only be incremented once during the whole experiment.
$this->pageview();
return $experiment->name;
}