[TYPO3] where is media/scripts/tmenu_layers.php ?

[Johannes Konert]

Hi members,
should be easy to answer this question (but I cannot figure it out):
Where is this tmenu_layers.php library I have to include for usage of 
TMENU_LAYERS via "includeLibs.tmenu_layers = 
media/scripts/tmenu_layers.php" ?
A "find -name tmenu_layers.php" did not find any file and I don't have a 
folder named "media"...neither on top-level nor in fileadmin.
Where to get this?
Thanks.
A puzzled
Johannes Konert
using: TYPO3 v4, dummy-package, debian sarge, mysql 5, php5