public StoredListIterator<T> establishListScan(boolean random_scan){
  if (isEmpty())   return null;
  StoredListIterator<T> slh=_SLHolderPool.get();
  StoredListIterator<T> res=establishPos(random_scan,slh);
  if (res == null)   slh.release();
  return res;
}

public StoredListIterator < T > establishListScan ( boolean random_scan ) { if ( isEmpty ( ) ) return null ; StoredListIterator < T > slh = _SLHolderPool . get ( ) ; StoredListIterator < T > res = establishPos ( random_scan , slh ) ; if ( res == null ) slh . release ( ) ; return res ; }
establish a scan position . if random scanning supported we select a random position
