/**
* Build the aggregation.
*
* @param BucketInterface $bucket Histogram bucket.
*
* @return array
*/
public function buildBucket(BucketInterface $bucket)
{
$aggParams = ['field' => $bucket->getField(), 'interval' => $bucket->getInterval(), 'min_doc_count' => $bucket->getMinDocCount()];
return ['histogram' => $aggParams];
}