func (q *FunctionScoreQuery) Filter(filter Query) *FunctionScoreQuery {
	q.query = nil
	q.filter = filter
	return q
}
Filter sets the filter for the function score query.
package elastic
type FunctionScoreQuery struct {
	query      Query
	filter     Query
	boost      *float64
	maxBoost   *float64
	scoreMode  string
	boostMode  string
	filters    []Query
	scoreFuncs []ScoreFunction
	minScore   *float64
	weight     *float64
}
func NewFunctionScoreQuery() *FunctionScoreQuery {
	return &FunctionScoreQuery{
		filters:    make([]Query, 0),
		scoreFuncs: make([]ScoreFunction, 0),
	}
}
func (q *FunctionScoreQuery) Query(query Query) *FunctionScoreQuery {
	q.query = query
	q.filter = nil
	return q
}