how to redirect multiple urls at pantheon

pantheon-301-redirects.php

// List of old urls and corresponding new target urls.
$redirects = array(
	'/url_01' => '/new-url-01',
	'/url_02' => '/new-url-02',
);

// Redirect multiple old to new urls.
// Note: make sure environment is set correctly
if ( isset( $_ENV['PANTHEON_ENVIRONMENT'] ) &&
     ( $_ENV['PANTHEON_ENVIRONMENT'] === 'dev' ) &&
     // Check if Drupal or WordPress is running via command line
     ( php_sapi_name() != "cli" ) ) {
	if ( in_array( $_SERVER['REQUEST_URI'], $redirects ) ) {
		$_SERVER['REQUEST_URI'] = $redirects[ $_SERVER['REQUEST_URI'] ];
	}

	header( 'HTTP/1.0 301 Moved Permanently' );
	header( 'Location: http://www.mydomain.com' . $_SERVER['REQUEST_URI'] );
	exit();
}