private function getFirstAndLastDataPointsForMetric($metric)
{
$first = 0;
$firstTable = $this->dataTable->getFirstRow();
if (!empty($firstTable)) {
$row = $firstTable->getFirstRow();
if (!empty($row)) {
$first = floatval($row->getColumn($metric));
}
}
$last = 0;
$lastTable = $this->dataTable->getLastRow();
if (!empty($lastTable)) {
$row = $lastTable->getFirstRow();
if (!empty($row)) {
$last = floatval($row->getColumn($metric));
}
}
return array($first, $last);
}