/** * Returns the week of the year for a date as a number between 0 and 53. * * The argument can be any expression as long as it resolves to a date. * * @see http://docs.mongodb.org/manual/reference/operator/aggregation/week/ * @see Expr::week * @param mixed|Expr $expression * @return self */ public function week($expression) { $this->expr->week($expression); return $this; }