Improper constant definition generates php notices

In the first few lines of the module, where three constants are defined, because the constant names are left without quotes, they generate "assumed constant" notices.

define (PAGE_THROBBER_VIS_NOTLISTED, 0);
define (PAGE_THROBBER_VIS_LISTED, 1);
define (PAGE_THROBBER_VIS_PHP, 2);

should be:

define ('PAGE_THROBBER_VIS_NOTLISTED', 0);
define ('PAGE_THROBBER_VIS_LISTED', 1);
define ('PAGE_THROBBER_VIS_PHP', 2);

I know. Nit-picky. : )