public function in($expression, $arrayExpression) : self
    {
        $this->expr->in($expression, $arrayExpression);

        return $this;
    }
public function in($expression, $arrayExpression) : self
    {
        $this->expr->in($expression, $arrayExpression);

        return $this;
    }
public function in ( $ expression , $ arrayExpression ) : self { $ this -> expr -> in ( $ expression , $ arrayExpression ) ; return $ this ; }
Returns a boolean indicating whether a specified value is in an array.

Unlike the $in query operator, the aggregation $in operator does not
support matching by regular expressions.

@see https://docs.mongodb.com/manual/reference/operator/aggregation/in/
@see Expr::in

@param mixed|Expr $expression
@param mixed|Expr $arrayExpression
Returns a boolean indicating whether a specified value is in an array .