lib/Elastica/QueryBuilder/DSL/Aggregation.php
public function date_histogram(string $name, string $field, $interval): DateHistogram
    {
        return new DateHistogram($name, $field, $interval);
    }
public function date_histogram(string $name, string $field, $interval): DateHistogram
    {
        return new DateHistogram($name, $field, $interval);
    }
public function date_histogram ( string $ name , string $ field , $ interval ) : DateHistogram { return new DateHistogram ( $ name , $ field , $ interval ) ; }
date histogram aggregation.

@see https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-bucket-datehistogram-aggregation.html

@param string     $name     the name of this aggregation
@param string     $field    the name of the field on which to perform the aggregation
@param int|string $interval the interval by which documents will be bucketed

@return DateHistogram
date histogram aggregation .