Source

File: wp-includes/rss.php

function __construct( $base = '', $age = '' ) {
		$this->BASE_CACHE = WP_CONTENT_DIR . '/cache';
		if ( $base ) {
			$this->BASE_CACHE = $base;
		}
		if ( $age ) {
			$this->MAX_AGE = $age;
		}

	}