public function replace( $args, $assoc_args ) {
		list( $key, $value, $group, $expiration ) = $args;
		$result = wp_cache_replace( $key, $value, $group, $expiration );

		if ( false === $result ) {
			WP_CLI::error( "Could not replace object '$key' in group '$group'. Does it not exist?" );
		}

		WP_CLI::success( "Replaced object '$key' in group '$group'." );
	}