question: void commit ( ) { if ( _mods . isEmpty ( ) && _dirtyList . isEmpty ( ) ) { return ; } UpdateRequest update = _dao . prepareUpdate ( _name ) ; List < UUID > uuidsToRecycle = Lists . newArrayList ( ) ; for ( SegmentMod mod : _mods ) { mod . persist ( update ) ; } for ( Runnable extra : _extras ) { extra . run ( ) ; } for ( Segment seg : _dirtyList ) { persist ( seg , update , uuidsToRecycle ) ; } checkWritesAllowed ( ) ; update . execute ( ) ; _uuidsToRecycle . addAll ( uuidsToRecycle ) ; _dirtyList . clear ( ) ; _mods . clear ( ) ; }
target:  Write changes to disk. 