$_params
$_params : array
Params.
Constant score query.
This function can be used to handle params for queries, filter
__construct(\Elastica\Query\AbstractQuery|null  $filter = null) 
                Construct constant score query.
| \Elastica\Query\AbstractQuery|null | $filter | 
setFilter(\Elastica\Query\AbstractQuery  $filter) : $this
                Set filter.
| \Elastica\Query\AbstractQuery | $filter |