/**
* @param Event $event
* @param \FlotChart $chart
* @param OphCiExamination_VisualAcuity_Reading $reading
* @param string $side
*/
protected function addVaReading($event, \FlotChart $chart, models\OphCiExamination_VisualAcuity_Reading $reading, $side)
{
$series_name = "Visual Acuity ({$side})";
$label = "{$series_name}\n{$reading->element->unit->name}: {$reading->convertTo($reading->value)} {$reading->method->name}";
$chart->addPoint($series_name, Helper::mysqlDate2JsTimestamp($event->event_date), $reading->value, $label);
}