Returns an opaque serial number that represents the state of the set
of registered types. Any time a type is registered this serial changes,
which means you can cache information based on type lookups (such as
gobject.global.typeFromName) and know if the cache is still valid at a later
time by comparing the current serial with the one at the type lookup.
Returns an opaque serial number that represents the state of the set of registered types. Any time a type is registered this serial changes, which means you can cache information based on type lookups (such as gobject.global.typeFromName) and know if the cache is still valid at a later time by comparing the current serial with the one at the type lookup.