Could somebody explain to me exactly what this DCOP function does:

void newUniqueIdForFile(QString path) Generates a new unique id for file at path.

What does "unique id for file" mean?

Does this function add the file to the collection database if it is not already in the collection?

Update: Even though this function is in the documentation it looks like it has been removed from Amarok. Testing the dcop functions from the command prompt does not list the function as available in Amarok 1.4.8