public function sample(int $size) : Stage\Sample
    {
        $stage = new Stage\Sample($this, $size);
        $this->addStage($stage);

        return $stage;
    }
public function sample(int $size) : Stage\Sample
    {
        $stage = new Stage\Sample($this, $size);
        $this->addStage($stage);

        return $stage;
    }
public function sample ( int $ size ) : Stage \ Sample { $ stage = new Stage \ Sample ( $ this , $ size ) ; $ this -> addStage ( $ stage ) ; return $ stage ; }
Randomly selects the specified number of documents from its input.

@see https://docs.mongodb.org/manual/reference/operator/aggregation/sample/
Randomly selects the specified number of documents from its input .