public function getStates(\DateTime $start_date, \DateTime $end_date, $reset = TRUE)
{
$events = $this->getEvents($start_date, $end_date, $reset);
$states = array();
foreach ($events as $unit => $unit_events) {
foreach ($unit_events as $event) {
$states[$unit][$event->getValue()] = $event->getValue();
}
}
return $states;
}