question: private void copyArrays ( ) { String [ ] oldSyms = _symbols ; int size = oldSyms . length ; _symbols = new String [ size ] ; System . arraycopy ( oldSyms , 0 , _symbols , 0 , size ) ; Bucket [ ] oldBuckets = _buckets ; size = oldBuckets . length ; _buckets = new Bucket [ size ] ; System . arraycopy ( oldBuckets , 0 , _buckets , 0 , size ) ; }
target:  Method called when copy-on-write is needed; generally when first change is made to a derived symbol table.